Hiya!
From "Lightest" to "Heavyist" in terms of rules...
Dungeon World + Apocalypse World: This might do the trick. It REALLY does require that the GM and the Players all be on the same page, working together, to create 'the world and story' though. If you want total control over the 'world' or your players are ones to not enjoy this aspect (or, worse, deliberately try and "screw it up"), this might not work so well.
D6 System: This is the old system from WEG (West End Games). You can find the PDF's online or pick up used copies all over the place if you look around (internet). It's a 'dice pool' system, but pools rarely crest 7D, and it's super-sleek in terms of how it runs. Everything is handled with a TN and a roll. Because of the way it is, you can use D6 Space, D6 Fantasy, and any other D6 book all at the same time with very little finagling (if any).
Masterbook System: This is a bit more crunchy, but in all honesty you can easily just ignore half the modifiers and the game will run just fine (typically what I do). It's a 2d10 based game with simple bonus chart on the bottom of the character sheet. A result is generated and that is looked on a single 'universal table' that has results for the "tasks/effects" of the game. The company that owns the whole Masterbook stuff is Precis Intermedia Games (
http://www.pigames.net/store/default.php). They do have one 'game' that sounds like it may be exactly what you want...maybe...
Bloodshadows (
Masterbook [older version;
GenreSystem [new version]): They/he just released a new version of this game, here:
http://www.pigames.net/store/default.php?cPath=129 It is a "Fantasy Noir" rpg though...not sure if you wanted modern day or not. It's basically "1930's...but with magic". I have the PDF's of the Masterbook (older) version and it sounds like it would be a really fun change of pace for our group. One day I'll run it...one day... As I've never played the new, GenreSystem version, I can't comment on it's crunch specifically, but if it's anything like Masterbook, it shouldn't be to hard to grasp.
OH, one important last point about the Masterbook System: It has the "Drama Deck" and "Plot Deck" you can use.

Check it out on the PIGames site...basically they are cards that really add a VERY cool dimension to the game as it plays! I
HIGHLY RECOMMEND using both the Drama and the Plot decks together! Great stuff to keep everyone's imagination and story-focus going around the table!
^_^
Paul L. Ming