I got the technique down for MGS1 so I can do it on the first try no problem (if you can't tell, that makes me cool)
The only games I can really remember giving me problems are shooters this generation. It started with Metal Gear Online with MGS4. It's pretty much my index and middle finger on my right hand, because that's the trigger pulling area. It started getting real bad with MW2, but the worst was probably going for the Platinum Trophy in Killzone 2, where the hardest one is to place in the top 1% of worldwide players for a week. I think I attempted it 3 times. I'm sure it was brutal.
So it happens every now and then and I get really worried about how my joints are going to be when I'm older.