I've been reading over Savage Worlds and Basic Role-Playing, both are universal systems that are nowhere near as crunchy as GURPS or Hero.  I'm really digging both systems and trying to get something going with my group when the current GM takes a break, just to try it and see how it goes. 

Savage World seems to default to a high action style game but the GM can make some modifications to make the game a bit grittier.  This one is really cheap to check out at $10 for the core rule book.  It has all the rules you need and various settings may have special rules and extra Edges, Hindrances, and Skills.
Test Drive rules can be found at Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or
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BRP is more on the gritty side, dying is fairly easy so it encourages players to think outside the box a little with confrontations (there is an optional rule that will give the PCs more HPs than the standard way, this could be used for more action or dungeon crawl type games).  Percentile based skill system.  I really like the way this is handled because the character has an opportunity to advance based on what they learned by *using* the skills they have.  There are the standard ruleset and a variety of optional rules to modify certain aspects of the game.
This is the same core ruleset that is used in Call of Cthulhu, the original RuneQuest games, Stormbringer, ElfQuest, etc. This book runs around $40 and weighs in at about 400 pages.
A free BRP Quick-Start can be found at Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or
YouTube Review:Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

I figure it would be easier to point you to the free test rules for you to get a feel for the systems than try to explain the rules in to much detail. The thing to keep in mind with both of these core books is that they do not include any setting, just the rules that are needed.

you could get an older edition of the Hero system pretty cheap. Theres a ton of stuff out there for it. It works fairly well with anything but it can be a chore to run.

Still settings are usually the hard part. If you have a setting in mind adapting the rule set is a matter of taste.