Ghost Squad -- I like the odd lightgun game and this is one that came out recently enough that I never played the coin-op version. It's faithfully emulated (4:3 display mode), but adds a lot of replay value in the form of unlockable weapons, alternate outfits and hilarious play modes like the ninja one where grenades are replaced by nori-wrapped rice triangles (brilliant!). In addition there are alternate paths to unlock for each of the three levels. Combine this with cheesy dialogue which is badly written (and amusingly delivered -- I have to think intentionally) and a budget price and you have a title any lightgun fan should enjoy.
House of the Dead: Overkill -- The gameplay is good with excellent use of special effects and quick arcade action with 1 or 2 players. Sadly the story is permeated with purile juvenile language and gross-out humour and just isn't my thing. I traded it in after one playthrough; if you like films like Dusk 'Till Dawn you may want to give it a look.
Kororinpa -- A game with a decent following I purchased on recommendation from a fan. Really it's not a bad game; it's just not a game that grabbed me. Probably it's down to tilting the platform to roll the marble. I'd rather have had the wiimote move the marble alone a la Marble Madness.
The Legend of Zelda: Twilight Princess -- My first (and possibly only) Zelda game. An enjoyable action fantasy title with good controls and a compelling (and at the end surprisingly touching) story. It's longer than I normally like to spend on a game without a strategy component, but never feels cheap: bosses aren't recycled and there's no mandatory backtracking.
I didn't like the fact that I had to consult walkthroughs at a couple of points (that lame statue puzzle -- you know the one I mean) and the final boss battle went on longer than I thought was necessary.
Considering I only bought this game to install the Homebrew Channel on my Wii, I'm quite pleased I took the time to play it; I just don't see any replay value in it. I understand all Zeldas follow a similar pattern; if that's the case I'm not likely to buy the next one in the series.
Little King's Story -- Possibly the best 3rd party game on the Wii right now. A great little light sim/strategy game where you take your little king and a small pool of followers and try to conquer the world. The control is simple and works well, the look and feel are charming with dark, wry undertones (could that be a subtle critique of war I'm seeing?) and the whole package is simply excellent. Fantastic effort from the devs and we have Rising Star to thank for bringing it to us in the UK -- cheers guys!