Fire Emblem - I haven't researched it much, but it just seems too deep and lengthy for me to really devote enough time to beat the games. I keep seeing Awakening on my shelf begging to be played and I just keep passing it by. Maybe someday.
Golden Sun - Same reason as above, honestly.
Pikmin - Despite the high praise for the series, it just never looked that fun to me.
Animal Crossing - Same reason as Pikmin.
It'll be awhile before I figure out how to do one of these. :P