Browsing the web on a phone sucks. I had all those features for free for a month on my current phone, and I didn't even bother downloading a wallpaper for it.
I'll assume you actually want a phone to talk on, in which case 3G doesn't matter, except in so far as it is associated with the best cellular networks.
Sprint's CDMA network is good, and it's a good standard. Arguably it has the best way of dealing with an overloaded network, but it's not like it's the only network that can do data. Sprint uses 1900 MHz CDMA. There is both 1900 MHz and 800 MHz CDMA, and 800 MHz is actually better in buildings. 1900 MHz is what they call PCS.
Cingular has the best converage in the US. AT&T, Cingular and T-Mobile all use GSM. GSM networks use GPRS for data. GSM also functions at 1900 MHz and 800 MHz. The reason GSM coverage is better than Sprint's coverage is because old TDMA networks can easily be upgraded to GSM. GSM coverage is good enough now that in most places there's no need for a multi-band phone.
If you live out in the middle of nowhere, AT&T has a local plan which lets you roam for free anywhere in your state on any GSM network. Then you get a GSM phone that will hop to Cingular if they have a better signal. AT&T is also really good about giving you promotions and then letting you keep them forever. I got a 250-minute plan with free nights and weekends and free roaming for $29.99/mo, and I got them to give me an extra 100 minutes/mo permanantly.
If you get a decent brand current generation phone, your provider is the most important thing.
I've never really had much of a problem, but I'm told all cellular companies have horrible customer service.
You don't want to get a cell phone in a store or mall or whatever. You get a much better deal if you research plans online and then call them up and have them send you the phone. For example, Cingular stores around here will not give you a free phone, but if you go to their website, you'll see they have several free GSM phones they'll give you with a contract. You still don't want to get a phone online, though. Just call up their 1-800 number and you can get them to give you the same deals as on the website.
I don't think Sprint will give you any free phones except their worst model, but I think they still give you better deals online. So just go to the store and look at the phones, then look up the plans online to find the best deal, then call them up to order one.