Yah I check out what you're playing every once in awhile NH, you absolutely destroy each game you get into it seems... Especially Saint's Row 2, ugh, I can't even imagine doing all those missions again co-op or doing those damn activities.
Soon you will find yourself doing the most ridiculous tasks for achievements. Once upon a time I could operate without them, now I take the quickest and dirtiest route for them. For instance, you know you've got it bad when you play the Avatar game, which will net you 1,000 points in under 30 seconds.
And if you ever get fed up with Left 4 Dead achievements, let me know, I know all the dirty ways to accomplish the hardest ones... but like I said, maybe you're still in the honorable path of achieving.