I prefer Achievements, by far.  The only thing I'd like to see changed is that XBLA Games don't get the credit they deserve.  Some of those games are pretty long and tough as hell yet, they are only worth 200pts total.  It's sometimes harder to get 50 points in an Xbox Live Arcade game than it is to get 700 points in a full retail game.  it's a little off balanced.

Prefer Gamerscore because every point you get feels relevant in some way, unlike trophies. Plus trueachievements.com covers those needs for X360 gamers wanting to see how their gamerscore stacks up according to difficulty without all the needed mumbo jumbo.

Some people have stated that getting all Achievemnts in a game doesn't have any value.  I disagree.  There's an entire page on your Xbox Live Profile when you're on your Xbox 360 that shows the games you totally maxed out.  I feel a little pride everytime I see it.  It's the page before your Achievements when you click on "My Profile".

I compare Achievements with everyone on my Friend's list almost weekly, too.  --Especially in games like Street Fighter or any new release I buy on day 1.

I didnt know that existed till my mate told me about it. It took me 2-3 years to platinum a game haha

That wouldn't work, either.  The reason is that some Achievements are VERY hard to get and only give you 25, 10, 1 or even NO Achievement points.  There's just the prestige that comes with getting them that makes them worth it, not the points.

gamescore man i like trophies but gamerscore seems like your gaining every point.

So it's not really a "preference"

except when they make really hard ones like 1 point to piss you off... jerks -.-

lol yea i hate that.

You can easily check how many games (XBL or Retail) you've completed on your mygamercard page. I always take a quick look just to see how I'm doing. ;-p

Anyway, I prefer GS over Trophies. It's always nice to get that little pop-up especially when you've been trying to get an achievement (like when I was trying to get the final ME1 achievement just recently!)

Trophies just don't do anything for me, I haven't even sync'ed my trophies in several months (I have wi-fi turned off on the PS3). Some of the systems most popular games don't even support trophies (older ones, the most obvious example being MGS4). Maybe if Sony had chosen to do Trophies right from the start then they would have more relevance...