Android is great.
Samsung Capitivate: Crap, slow, and old.
Samsung Galaxy S II: Lilac has it. Get it if its available.
Samsung Galaxy Infuse 4G: Get it. Great phone.
HTC Inspire 4G: I got it. Get it. Great phone. Awesome hardware. Love it.
Check it. AT&T has a Mobile to Any Mobile plan, which is free calls to any cell phone. So that should save you some minutes. 450 minutes is good, and if you text more than you talk, then its perfect for you.
Still, All together, You're looking at $30 for Data, $20 for texting and $60 for minutes. With a google phone, you can use Google voice, and pretty much use GV with anyone else who has it for free minutes.