Microsoft needs to get their act together on their achievement system. Sony lagged behind during the PS3 days, but now it's trophy system is superior.
Biggest problem is glitched achievements. I'm not saying Sony doesn't have glitched trophies but I have yet to see one.
Microsoft, on the other hand, is currently a mess. It's bad enough that the XBox One will have achievements that track at 100% but won't pop for a week, but the number of glitched achievements in things like Games For Windows Live, Windows 8, and Windows Phone are beyond frustrating.
Add in cross platform games like Total Conquest which appears on both Windows Phone and Windows 8 and shares the achievement list but only pop on the system you get them on so you have missed achievements on one of the platforms, and it really makes me wish I had obsessed on trophies instead of achievements.
Microsoft, get it together.