That Final Fantasy one is definitely interesting in it's own way. As others have mentioned, it's more of a city building simulation, like sim city, minus the somewhat more complicated things and the random destruction all over the place. The cost can add up to quite a bit eventually though, since I think add-ons will keep being released over time. It is surprisingly addicting though. My longest time on it was a bit over 7 freaking hours... that's a new record. Not that I'm complaining though; Everyone else just does.
Another one I have purchased and has been worth it so far, is Pop. Popping bubbles; doesn't sound much fun does it? Not much to do BUT to pop bubbles basically. But, people can find amusement popping bubble wrap, so it's almost the same, 'cept you won't run out of bubbles to pop. It can get surprisingly crazy once you get to higher 'waves' (levels I guess), and you'll find time being taken away from you from those blasted skull-marked bubbles... but it can get competitive with multiplayer too, since power-ups to hinder each other's progress with getting a high score come up very frequently. I mostly got this though since I try to find games that others can play with me, since I am the only actual gamer. Nothing more simple than popping bubbles. The music can sound quite nice sometimes, if it doesn't get tones out by the bubble noises. And, the wii remote vibrates everytime to hit a bubble, or even miss, so its like you're getting a hand massage.
One I have not obtained, but seems to be one of the better wii ware titles in my opinion, is that Dr.Mario Online Rx or something. I haven't played the old version, but it looks to be a tetris-type game. I guess you can also use your Miis in it, and compete online. Erm... that's all I can tell since I don't know much about it.
I don't know of any other wii ware titles to be released in the future though, save the Pokemon Ranch.
