Some of our houserules in effect:
-No Availability limit at chargen. Never have, never will. If we play a ganger game we just say it and the table picks gear of an appropriate nature.
-When we used BP, Cha x2 free contact points.
-Much more lean limits on meta augmented maxes(if you start buying and optimizing limbs, you can go crazy. With the underlying message of 'watch the Agility.

)
-No hard cap on skills. Chargen limits still apply as RAW, however(one max stat, and skills as RAW as well-1 6, rest 4 or less, etc.)
-SR4 attribute enhancement rules in effect(since these are houserules now.) We use x3 stat advancement; we don't play every week, and sometimes go over 6 weeks between a game, so x3 is not too fast at all. Since our Karma awards are only 4-7 a session, depending on things, that actually makes x3 somewhat slow, even. (For the record, we stick with the SR4 rules. I honestly do not like almost all of the SR4A changes for my games and neither does our other GM after we talked about it. So I suppose if you consider simply that ''we play an older edition'' at our table, this is not a houserule.)
-Little things. We added a few more small windows in which one could make an Intercept attack, for example.
-Houseruled gear. In other words, we just make up some gear that's not in the book. Multi-tools, quick-draw sheathes for melee weapons, hardliner boots(in other words, steel reinforced.) Most of this stuff is common-sense little stuff that would probably exist anyway and they may have forgotten. We're perfectly happy to help out if someone suggests some gear not in the book; we check out it's real-life price, and try to fix a rating on it.
It may seem like our house rules explode power, espeically since we use the SR4 rules and the 750 Karmagen, but our typical die pools for the high end run between 13-17, so it really doesn't explode things. It just gives us the level we like to play.