In a niche sub-genre Fire emblem is the best thing going. Turn based fantasy strategy.

User Rating: 9.5 | Fire Emblem: Radiant Dawn WII
If you like chess, you will like this game!!!! If you have not played Prev. FE or even the GC game, which this is the sequel to, you can pick up this game and get into it pretty easily. Basic strategy is key, aka dont put your mages/archers in reach of enemys. use them to blast at the beging of the turn, then push your front line melee up so enemies cant reach your mages. Try to keep your guys shoulder to shoulder rather then staggered, this ensures you guy cant get ganked and also build up the support they get from neiboughs. I dont find the game to be any more difficult then Advanced wars, and in fact I much prefer the fantasy versions of the Turn based strategy because you get to keep your units and develop their skills/atributes rather then just buy new tanks when they die. it encourages you to keep your guys alive.
One of the best features FE for the Wii brings is "battle save" which allows you to create a save point anywhere in a battle which you can restart from infinite number of times. This was left out of the GC version, sometimes making you re-do 120 min battles cuz you lost a guy in the last turn. Unlike other genres like FPS or RTS, this genre(Turn based fantasy strategy) is almost devoid of development. You start with a game on the sega genesis - the Shining Force serries and move onto Fire Emblem and there is not much else available. Further to the additions to FE, now EVERYONE is available for support. this is great as in prev. FE versions you had to line up specefic team members to get these bonuses.