Cro-Mag Rally [iTunes link] -- I used to play this on the older PPC-based iMacs and it was also an early entrant to the store. Cro-Mag is cute but it also plays exceedingly well. If you want something like Mario Kart on your iPhone, this is about as close as I've found. For a quick racing game that nearly anyone can enjoy, Cro-Mag is a true iPhone "classic."
MotionX Dice [iTunes link] -- You never know when you're doing to need some dice. Plus, MotionX gives this app away, and it's a beautiful example of what can be done on the iPhone. When someone wants to "see something" on my iPhone, often I'll show them how the shadows cast by the dice change as I move the iPhone. Then we'll play some dice games.
Flick Bowling [iTunes link] -- There are faster, cheaper versions of bowling on the iPhone. I find Flick provides just enough eye candy and immersion to suit my taste. Plus, it loads pretty fast and you can get to bowling without a lot of setup. It's a casual game that looks bigger than it is.
Dizzy Bee [iTunes link] -- One of the big, early hits for the iPhone, in no small part because the super cute free version moved a lot of units. Dizzy Bee is the app everyone seemed to give to the kids to play with, but the challenges get pretty tough. Like any great game: simple to learn, hard to master. Plus, there's now a sequel.
Keep reading for some games that are a little more under the radar and some genuine iPhone essentials...
Endless Abyss [iTunes link] -- This one is great for kids, and the sounds are somehow extra soothing. It's the basic game of keep away (you tap and drag a little crab around the screen to keep him safe), and there are other games that feature more "stuff" (Pixel Pusher is a good example), but the straightforward nature and pleasant ambiance of Endless Abyss earns a permanent home on my screen.
Fieldrunners [iTunes link] -- Um, it's Fieldrunners. This is like the one game that everyone must own if you enjoy tower defense games. Seriously. I have tried dozens of "tower defense" games on the store (and there are tons), but I keep coming back to Fieldrunners, as do my kids. It's just a well-balanced, well-produced game. I will say that Star Defense is a very close runner-up.
Pocket God [iTunes link] -- There's a reason this winds up in the top 10 now and again: it is a lot of fun to torture little cartoony people in new and creative ways -- sort of like Tom and Jerry. The developers behind this app keep adding new content to the game by listening to feedback, making replay value high. Plus, I will somewhat abashedly say my kids love this one. If the content worries you, I recommend Pocket Fish [iTunes link] -- a cuter, gentler toy for kids.
Zombie Nombie [iTunes link] -- I used to show people Koi Pond as a "look at this cool 3D" example, but Zombie has taken its place. Koi Pond is great, but Zombie is a 3D interactive zombie head! Plus, there are several games baked in to the app and you can use it as a basic egg timer. With a slew of unlockables and a low price, this is a no-brainer.
Pharos IV [iTunes link] -- Perhaps one of the most under-appreciated games on the store. If you ever blew an afternoon playing X-Wing or Wing Commander, you'll be right at home here. Pharos has some of the best controls on any iPhone game I've played so far, and the graphics and sound and game balance can't be beat. Best of all, it is a quick pick-up game for when you just want to fly around and blast something. If you're looking for something more in-depth and with a story, check out the superlative Galaxy on Fire 3D [iTunes link].
Flight Control [iTunes link] -- Truth be told, my new love is Harbor Master [iTunes link]. It offers the same mechanism as Flight Control with a little more depth to the game. So, like Sang, perhaps I'll retire.
Sway [iTunes link currently unavailable] -- This is my favorite game so far. I played the Lite version [iTunes link] before realizing I simply had to try the other critters and levels in the full version. Once you get the hang of swinging around, you'll find this is a perfect example of leveraging the unique capabilities of multi-touch game controls versus the more simplistic "touch screen" game controls seen in most apps. The game isn't perfect, but the challenge is just right, the unlockables are timed perfectly, and the polish on the game overall is simply astounding. A must-have, and something you will want to show off to people who doubt the fun of the iPhone ecosystem.
For more reviews check out our new iPhone/iPod touch App Hub.