Do you guys actually beat all the games you buy? Doesn't seem like there's enough time in the day.
No.
Double no

I've been going on game shopping sprees, but they're usually used games so i dont talk about them hear much because i'd be like that guy who shows up to school/work and wants to talk about a movie that came out 5 years ago cuz it was exciting, but missed the chance to cuz everyone else has seen it a million times. I'll bring up a game purchase when its relevant, for instance picking up DK Jungle Beat + bongos.
Wii games i rarely get in abundance, obviously because of price, but i've been buying a good amount this generation. It's great to have the money to afford them so often, but i just dont have the time for them so i jump around from title to title. The last game i beat was The Godfather, then i jumped from Okami to Battalion Wars to a laundry list of old GC games, not beating any of them (came close to beating XIII though) and currently i'm jumping between GH:WT and Time Splitters: Future Perfect. Oh and Ikaruga, but i suck at that game and am waiting for my friend to come back to town so we can co-op it (and TS:FP). I thought i "beat" GH:WT last night but i just got the credits and unlocked a bonus tour, so i still have that to do before i can say i've completed it.
The biggest problem (when it comes to beating games) is being a completionist. Its still in the back of my mind that i have to go back and get more stars in Mario Galaxy, even though i beat Bowser/saw the credits. I know theres still a few tracks in ExciteTruck i've yet to get an S on and i need to unlock that one crazy level, and theres characters left to unlock in MK with a few more gold trophies, etc. Even when i beat the damn thing i feel i need to complete it to the fullest before i can stop feeling guilty about putting it down and collecting dust.
Back to buying games, though, I know the rest of this and all of next month i'll be trying my hardest NOT to buy any games, because i need to get my Xmas shopping in. I usually don't wait till this late in the year, but whooops! If i do buy any Wii or DS games, they'll be for my girlfriend, so she's the one that has to worry about finding the time to play/beat the damn thing.