I'm really not sure what the question is, so I'll just answer all of them.
Game that sucks me in the most (most addicting) - the Harvest Moon games. I started playing Sunshine Islands last night, planning on just watering my crops, giving Lanna a fish, saving my game and going to sleep. By the time I finally switched my DS off there was daylight outside and I'd gone through three seasons.
Games that suck the most (the gaming poisons of our time) - I'd have to say Shiren The Wanderer. What's the appeal of these games? I see no redeeming features to them at all. The way you move is incredibly annoying, the combat sucks, and losing everything when you die? Gimme a break. And don't even get me started on Lunar Dragon Song. I nearly died after playing that. The overdose of pure undiluted fail contained within that plastic shell totally crippled my faith in gaming. I had to play the NES Megaman games for a fortnight before I started to recover.
Games I suck at the most - anything with motion controls. Absolutely any motion controlled game whatsoever. Being raised on the NES and Mega Drive I've gotten a little set in my ways. I love my D-pads. I can just about cope with the switch to analogue sticks. But I've never been able to get to grips with motion controls. The stylus I can use, but give me a wiimote and I'll show you a frustrated man throwing said wiimote through the window (cheaper to replace than the telly). My mind simply does not function while using them.
But for DS games I suck at, I'd have to say the Professor Layton and the Brain Training games. I'm not stupid by any means. But I play games for escapism. I play to avoid the necessity of thinking. so when a game forces me to actually think, I give up and play something else instead. Something mindless. Preferably with guns or zombies or something. Zombies! on my SNES, usually.