I don't know what your rush is, but rushing into a phone purchase is generally not a good idea.
Here's a bit more of a breakdown:
Motorola Backflip: Odd keyboard layout, low specs, annoying custom UI and an outdated version of Android. Cheap, but still, just pass it up.
Xperia X10: Large 4" screen, powerful processor, but low on RAM and also running an outdated version of Android, although an update is supposed to be coming it still won't be to the newest version. ight be on the lower end price-wise.
Samsung Captivate: Higher-end phone, 4" screen, latest version of Android, but there have been a slew of problems with the GPS and occasionally reception. Not cheap.
HTC Aria: Only slightly outdated OS-wise, mid-range specs, smallish 3.2" screen. Probably free with a new contract or upgrade.
Dell Streak: This is closer to a tablet than a phone, and from what I've heard performance is somewhat underwhelming. I don't know about the price range either.
Keep in mind any Android phone requires a data plan, and mommy and daddy might not be willing to shell out the extra $15 a month.
