Analog, digital, or PCS
Analog cellular's older technology is more vulnerable to eavesdropping and theft than digital, and rates tend to be higher. But analog's long life translates to the widest coverage -- worth considering if you need to make calls in less urban areas -- and phones are cheaper.
Within digital, your two options are cellular and PCS (which are often mistakenly used interchangeably).
Though digital cellular and PCS (personal communications services) offer some of the same features, PCS networks are far newer, so their coverage can be sparse in non-metro areas.
Unless your wireless needs are highly tied to the Internet, there's not much benefit in going with PCS over cellular -- unless, of course, you find yourself with a better deal.