jeez you have got to tell me the secret to getting the trophy for shooting the asteroids in the first one that is the only one I haven't got <.<
If you think that achievement is tough, try the no dying achievements in Dead Space 2 and 3. 
Kinda ashamed now about how my completion in general looks in comparison to that. I don't think I even have any 100% completes. xD
I've never actually 100%'d a game on live before.... I've got a couple that are soooooooo close to it that I really should have it, cept they're like play on the hardest difficulty or something.
I play these things for the story, unless its a RTS, but I digress, I play games for the story, not for the challegne, and thus I shall never actually have some of these games at 100% -looks at ME2's complete on Insanity-
I consider myself a completionist when it comes to games I actually enjoy (as a general rule). I've played a little over 100 games across the 360 and the Xbox One and I have roughly 50+ completed titles as of right now.
Looking forward to maxing out DA soon! 