I'm currently in the process of busting my team by Ares for failing to finish a recent job (they thought they did, but it turned out to be a body double). How do I make the interrogation interesting and memorable? (I mean besides lots of intimidation and torture)

Torture is a terrible interrogation technique, it puts the subject so at odds they'll lie to make it end, so the info you glean from it won't necessarily be true. Intimidation works great, threat of torture would fit in that as well. Personally, I'd go with pure mind fuckery.

Said above already, but despite what is seen on '24', torture is a very bad way to try and get information - it just plain doesn't work. If Ares is interrogating the group as a PUNISHMENT, by all means torture their little eye-sprockets out until those pretty cyber eyes explode. On the other hand, if Ares actually wants INFORMATION out of them, sleep-deprivation, a dosage of sodium pentathol, the 'Mind Probe' and 'Analyze Truth' spells, and a nice dark room with one bright lightbulb will do far better.
Overall, the Mind Probe spell totally removes any need for any interrogation, actually. And when I think about it, cast ' Mass Agony' on the party instead of torturing them for a punishment.

"This is between me, your Family Jewels, and this drawer"

If you want to make it realistic, you have to realize that intimidation, torture and other such things are completely useless in the Sixth World.
Spells like Analyze Truth, Mind Probe or even Alter Memory can get you what you want easily.
Drugs like Gamma-Scopolamine reduce the Willpower to 1 and are said to be "truth serums".
I'm pretty sure you can get good results with BTL or other technical form of mind-probing/mind-reprogramming.

If you don't care about realism, have fun with torture BTL (describe how the character is killed by his captors before waking up in front of them as they remove the BTL chip and explain that they'll do it for real if he doesn't speak) or spells.

Another way that could be interesting would be to have Ares put them in a simulation of a situation where the PC would be likely to reveal the information the megacorp wants.

Another wonderful option is to go almost completely against their expectations. Have them escorted from their dark, dank-ass containment cells skittering with devil rats with a floor covered in unmentionable fluids to a comfortably lit little room that wouldn't look out of place as the VIP room of a high-end club. Have the interrogator offer them champagne or whatever their alcohol of choice is, maybe with a few classy bits of nomage. And then just have him attempt to start chatting with them as if his company didn't just catch them trying to lift a weapons prototype from a top-secret lab.

When it becomes clear that the players and their characters are confused enough, have the Ares official explain that he was impressed by the character's hez in trying what they tried and that this sort of gravy train (complete with semi-regular employment in Ares) can continue. Just so long as they do him the small favor of ratting out their former employer. To make it extra tempting, see if Ares would be able to get any information on the individual runner's lives (acquaintances, family, girlfriends/boyfriends, any personal problems) and have the rep offer, in addition to a pardon a way to make said personal problems disappear (having Knight Errant drag away the scumbag harassing your girl, making sure your grandmother is comfortable).

This benefits Ares, because now they have experienced Runners with a debt to them, (along with knowledge of their weaknesses and personal lives that could serve as a way to strike back if the runners get cold feet) along with information on who tried to screw them over (and if I know Ares, they won't take that lying down). What's more, if word gets back into the shadows that the group is a bunch of snitches, then the only work they'll be able to find will be for Ares-thus cementing the corp's hold on the little jail-birds.

"Good Corp" can be just as effective as bad corp, if not more so-given that most characters and players won't really expect it.

Or you can go with--He joe runner, that sore spot on your arm is the injection point ofr some nanites. They'll kill you in 48 hours if you don't get the neutrilizing nanites. Oh and to get the neutralizing nanites, I have a job for you.

Torture doesn't work unless you have information that you already know. It's really a delicate process, but you want to make sure that you initially ask the subject your torturing questions that you already know the answer to, but he doesn't know you know the answer to. Once he starts answering all of those truthfully, then you move on to the questions you don't know. Like any interrogation method, you establish positives and negatives before you start looking into what you want.

Don't forget to separate them into different rooms so they don't each know whats happening to the others, then you can really mess with them, especially if you have say .. a scream sound track and some animal blood and parts to play with. Personally I like psycological torture over physical torture.

Man: "Look, this can go one of two ways. You can tell me what you know about (event), or I can hand you over to.....him." (man indicates Troll standing behind him)

Troll: *cracks knuckles*

Tell whoever you're playing with:"Let's just say he tells me what i want to know, everything he thinks i might want to know and everything i ought to know . . and in return, i won't have to tell you exactly what i am going to do to/with him"

i understand torture is a terrible interrogation technique, hence why it was on the besides list.

the idea of this interrogation is to see if they know anything about the body double they captured instead of the real target (which they don't) and then to force them to accept a longer mission that involves them tracking down and finding the real guy.

i like the good corp idea, perhaps in conjunction with a little psychological elements (cover the office in a fair amount of animal blood perhaps, or a rather disturbing trideo of the last person to not provide them with the correct information)

"When I ran safehouses in the anti-Marcos days the first order of business whenever a cell member was captured by the police was to alert the surviving members, move the safehouse and destroy all links to the captured person. That’s because everyone knew that there was a great probability that the captive would talk under duress, however great his bravery and resistance. Nobody I know, or have heard of who has had experience in real-life situations has ever said, 'our cell should continue as usual and the safehouse should remain open, despite the fact that one of our own is being tortured by the secret police, because I read in the New York Times that coercion never works.' The probability is that torture works and for that reason its use constitutes a moral dilemma; and the reason why Jacoby believes he is expressing a noble sentiment when he forswears it even as 'a last and desperate option' in the War on Terror."

"But there was another oath everyone in the underground tacitly made, which is structurally identical to Jacoby’s own. It went something like this: “I promise never to reveal the whereabouts of my companions to the secret police however brutally they torture me.” We all accepted this charge as a moral statement of intention, without deceit or mental reservation, yet without having the slightest certainty that we could carry it out. And the reason for the uncertainty was simple. Nobody actually knows how long he can last until he’s actually in the situation. Anybody who tells you different is probably a liar or fooling himself. Some will go further — much further — under duress than they think. Others will break right away. But nobody can predict it in advance."

One of my characters has a specialization in Torture, & has found it to be remarkably effective. Of course, she uses it for recreational purposes...

Load them all up with personafixes, make one of the members think they're the Ares interrogator. Then swap personality chips on them in a circular pattern.

Use body doubles of the team to kill off an annoying mid-level stooge in a competing corp. Give the team the option of either more mind games or they become "indentured servants" for at least a little while until Dermal Deposit Dan can come and give them a dribble deposit.

Plug them in to snuff BTL every night, so they wake up to really bad dreams. Role-play the "dream" and then tell them they wake up. Make sure the means of death is somewhat unique. Then one day, they're paid a visit by someone with that means.

You know some people actually are into the extremes of this sort of thing.

Ares interrogator 1: You know torture doesn't work on them.
Ares interrogator 2: Why? I've always had good result with it.
Ares interrogator 1: You know the concentration camp where I moonlight? They go in for recreation.

Bill Murray: I have a history of dental problems.
Steve Martin: Shut up!
Bill Murray: *melts* Yes doctor. *skips into the office*

Holds up a handgun.
"You see this? This is an (insert handgun of choice)."
Holds up a magizine of capsule rounds.
"You see this? These are capsule rounds loaded with the Kriger strain of the HMVV. Lie to me I dare you."