Having bought a rare version of the Leading Edge Aliens RPG, I can attest to how tricky the detailed skill system and WAY MORE COMPLEX firing/hitting/location/ damage system it uses is.....so switching to something else I can certainly get down with....
One thing I'd like to avoid though is switching to (old man time here, apologies in advance) some of these new "narrative game" systems that I just can't get down with.....i.e. the new Cortex system (I liked the original, the one they use for the second Firefly/Serenity and Marvel Superheroes game...Yuck...does NOT work forme).....my main issue is that I'm not a big fan of each and every poster being able to take the story any which way as otherwise, we're not playing a game anymore, we're all just putting in parts of a novel and that's not what I signed up for. To me, the game results bring out the narrative NOT each person rolling dice and on "I got a die with a triangle and another with a square and the last with a circle....so that means I succeed, but with a consequence, so hmmmm, let me make some sh$t up right quick"....that just doesn't work for me personally.
On the other hand....the GM saying...."Okay, 2 aliens rush Samantha and get within a few yards as they hiss and their spiked tails arch up behind them, ready to strike!"
I then post...."Eyes bulging out in fear, Sam rapidly cut loose a pair of 6 round bursts from her Pulse Rifle as she backed up and yelled out "A LITTLE HELP OVER HERE!"....
and behind the scenes the GM rolls some dice, gets results that take out both aliens, but one of them splatters enough acid blood to hit Sam and then posts THOSE results....now that works for me.....and some might say "What's the difference?".....to me, the difference is that it's the GM's job to make that interpretation, not each player to do that (I'm talking in 'scenes that matter'....it's fine to let players make up whatever in non 'important' situations as long as it doesn't get out of control).....I hope I'm not the only one that feels that way. If I am, please let me know and I don't want to get in the way of anyone else having fun and I'll move along back to the old peoples' home.
As for a different system, I think both d6 and Ubiquity (powers Hollow Earth Expedition) would work easily......for d6 all skills fall under a specific Attribute and it would be easy to quickly set up something to scale each skill like: "Grand Master equals: +6 dice, Master equals +5 dice, Expert equals +4 dice, Proficient equals +3 dice, Competent equals +2 dice, Novice equals Attribute rating +1 dice, Unskilled obviously means just Attribute rating.
Assume the following Attribute change/mods....range is from 2D (lowest), 2D+1, 2D+2, 3D, 3D+1, 3D+2, 4D is the highest...with 3 points or "pips" per die.....18D for 6 attributes....so 3D+2 and 2D+1 in another attribute would add up to 6 of the 18 dice for attributes, if that makes sense) So Sam Hall might look something like this: (New Attributes in bold....old attributes in parentheses)
STRENGTH/STR (a combination of the current STR and Health attributes): 3D
MIND/MND (a combination of Intelligence and Motivation): 3D+1
REFLEXES/REF (a combination of Agility and Perception): 3D+2
CHARISMA/CHA (a combination of Charisma and Leadership: 3D
MECHANICAL APTITUDE/MECH (essentially an attribute for Flying ships, working Motion Trackers, Driving the APC, firing ship based weapons, etc.): 2D+2
TECHNICAL APTITUDE/TECH (essentially an attribute for fixing things and computer wizardy, etc.): 2D+1
And then slot the skills under each....so Gun Combat under REF, Motion Tracker under MECH, etc. And Sam has Master for Gun Combat so that's 3D+2 +6 dice so 9D+2....Sam is bad ass with a Pulse Rife....but she's unskilled at fixing an APC...so if the APC throws the trans-axel and she has to try and fix it, she's just rolling her TECH of 2D+1....not good!
Difficulty numbers are typically (assuming the D for Dice used is a d6): VERY EASY tasks: 5, EASY tasks: 10, MEDIUM tasks: 15, DIFFICULT tasks: 20, VERY DIFFICULT tasks: 30
If your skill is 5 dice...you roll 5 dice, add them all up and see if you beat the Difficulty number. If you need to know HOW well you accomplished something or failed, you can do stuff like +5 over the Difficulty one step UP /Down.....or Twice the Difficulty number means you REALLY DID WELL at it, etc.
Anyway, I can go on about it if anyone is interested.
The Ubiquity system is similar excpet instead of adding dice together if you roll 6 dice, you only add up the even results to see how many successes you got. Typically like above, the difficulty number is a sliding scale so 1 success is needed for Very Easy, 2 for Easy, 3 for Moderate, 4 for Difficult, 5 for Very Difficult.
Obviously things like taking cover, multiple actions, opponents actions, etc. can tie into this, but both systems I find very straightforward and work VERY WELL with any non Magic/Supernatural/Super Heroic etc. kind of setting.