If your team had to make one last heist, to retire, to save your reputation, or for old time's sake, what would you do?

Shadowrun is at least partly based in wild Heist movies. Heat, Ocean's Eleven, Leverage, The Italian Job... What would you steal in the 6th world? Valuables or trophies? What complicated plans would you create to out-smart your opponents instead of out-gunning them? What crazy stunts and/or equipment would you need?

What high-profile target would you hit to make sure you go down as legends?

What crazy scenes can you end with? Helicopter chases? Escaping on hang-gliders downtown? Fireballs as you walk away?

Hmmm...I'm rather tempted to first start by listing what I wasn't willing to do. After all, living to spend your ill-gotten gains is the name of the game. Steal from a dragon (or the mob) and they'll keep looking for you, even if it takes decades.

I would probably go with a massive data heist - some knowledge locked away either by one of the Megas, or a Dragon / Immortal Elf. Bearing in mind JanessaVRs comment above - mostly I'd go with this as the knowledge is ephemeral. Once it's out there, it's forever shared. There's no physical product to get back, nothing to recover. Whoever you stole it from might be ticked with you, but there's no point chasing you and hunting you down directly - they can't get back what you stole. I mean, they might still do it just to prove "never deal with a Dragon", but it will be just because they're a sore loser.

Publishing the details of every immortal elf and all the genology details from the Tir database for instance, would make your name worldwide...and I'm sure someone would pay for it.

Classic "heist items" such as crown jewels of Farawayastan or masterpieces of some famous painter would most likely be even more expensive than they are today. The problem is that you can't really sell the Mona Lisa.

So if you want a really epic target, I would suggest something akin to the Big Maple Leaf. It's a huge chunk of gold that can be melted down and sold in inconspicuous increments, which is most likely what the real thieves did...

Every day is a school day. The word to describe that is "Fungible"
For a full definition see Fungibility - but the short definition is that you can take a gold ring, melt it down, cast it into a new gold ring and though it now no longer looks like the original (just like the Maple Leaf, above) it's still equally valuable. In theory you could own a gold ring that has history all the way back to Spanish conquistadors raiding the Aztech empire (let's just hope the background count has faded...