First of all, my site, Modojo, takes mobile games seriously. We've reviewed over 200 of them. I personally have probably reviewed at least 100. Besides us, IGN's wireless channel is also great - the editor is a stand-up guy and bags on the bad games and praises the good ones. His opinion overlaps most closely with mine out of all the people writing about mobile.
http://www.modojo.com/mobile/
http://wireless.ign.com
Other resources include:
http://www.wgworld.com
http://www.quicklybored.com
http://www.mobilegamefaqs.com
http://www.midlet-review.com (Europe)
http://www.pocketgamer.co.uk (Europe)
Second off, you'll learn that way moreso than in the console world, quality really IS company-dependent. EVERY mobile game company has some stinkers, but in general Digital Chocolate, Glu, and Gameloft put out good stuff (excluding gameloft's 2D platformers). That's not to say you should ignore Namco, Capcom, Sega, EA Mobile, I-Play etc. - but just know that their titles aren't as universally high-quality.
Third - let's get into the games.
TOWER BLOXX
http://www.modojo.com/reviews/mobile/tower_bloxx/20060824/367/
Half timing/rhythm, half city-building
SUPER KO BOXING
http://www.modojo.com/reviews/mobile/super_ko_boxing/20060731/356/
A spiritual sequel to Super Punch Out
ROLLERCOASTER RUSH
http://www.modojo.com/reviews/mobile/rollercoaster_rush/20060907/375/
Go fast enough to make the riders happy, but too fast, and you'll crash...
GHOST RECON 2
http://www.modojo.com/reviews/mobile/ghost_recon_2/20070517/511/
It even has a cover system
TIME CRISIS
http://www.modojo.com/reviews/mobile/time_crisis_mobile/20060113/195/
The screen is split into a grid, and you press the numpad to fire in that section. Works surprisingly well.
DINER DASH / ZUMA
Most mobile ports kinda suck, but both these are GREEEAAAAT translations, that control really well, and have more depth than most mobile releases.
http://www.modojo.com/reviews/mobile/diner_dash/20060313/252/
http://www.modojo.com/reviews/mobile/zuma/20060412/288/
TRIVIAL PURSUIT MOBILE DELUXE
http://www.modojo.com/reviews/mobile/trivial_pursuit_mobile_deluxe/20070326/487/
Don't laugh; it seamlessly pulls new questions down from a central server, has online multiplayer, a question of the day, etc. A great package for trivia buffs.
PEOPLE'S CHOICE HANGMAN
http://www.modojo.com/reviews/mobile/peoples_choice_hangman/20070509/505/
Again, don't laugh. You can submit your own puzzle packs and download new themed word packs as well. A nice diversion.
NIGHTMARE BEFORE CHRISTMAS
http://www.modojo.com/reviews/mobile/tim_burtons_nightmare_before_christmas/20061212/442/
Wait, hear me out. This one is actually an oldschool, top-down block pushing puzzle title, like Lolo. It also has over 75(!!) levels.
Super Boom Boom
http://www.modojo.com/games/mobile/super_boom_boom/
It's all about timing. You must pitch a bomb upwards into a series of moving baskets, to reach the top of the stage. It starts out as just baskets, but before long pulleys, birds, poles and all kinds of other obstacles enter the mix.