Houses rules.. lets see..
I give free contacts (from 5 - 10 contacts with varying ratings) to my players, I write up a lil something about them, names, locations, occupations and some fluff.
Players start with 600 BP's to make their chars instead of 400. This gives slightly more powerful characters but luckily my players seems to be able to handle it by spending part of that on more knowledge skills and other fluff stuff which only adds personality but not game advantages.
Grenades go off when thrown (don't tell me grenades in 2070+ cannot be set to explode 0,003 seconds after they are thrown) - not on the next IP pass, the damage doesn't get modified for hitting walls etc though (not realistic, I know, but its a game - not a reality show

), makes them less lethal but more useful, this is a new one and only run with it in one session so far, but I like it.
BE YOUR CHARACTER - this is not as much a rule as its a guideline, but it keeps my players from abusing the rules by giving it a tangent to realism, for instance my mages don't overcast all day long because its more efficient - because - it gives physical drain, and no one wants to endure pain unless they have no other choice, in other words, but things in perspective, its a role-playing game, characters are persons, not machines (well, arguably low essence characters.. etc, but you get the idea)