I use T-Mobile and am quite happy with it; I pay $30 a month for basically everything I need and no contract.
It is worth noting, however, that T-Mobile has some serious problems. There are large swaths of this country where T-Mobile simply doesn't have service. For instance, last time I drove from Denver to Chicago I lost reception 1 hour into the trip and got it back a few hours before I arrived. There was perhaps one town where I had service during the drive. I thought that this couldn't possibly be right, but I stopped by a T-Mobile store and confirmed that this is the case. I thought that mobile providers worked to ensure that your phone would work at least when you are on an interstate, but not with T-Mobile.
Also, unlimited Internet doesn't really mean unlimited Internet in practice. They throttle so heavily after I hit my 5 GB cap that they might as well have cut off the data plan. Programs stopped working as the requests would time out and the app would assume I had no connectivity.
I use/abuse my T-Mobile plan at times and at others barely use it at all. It all averages out to a pretty light to moderate usage, I figure. One of the reasons I really like T-Mobile is that they have never really bothered me about it.
The worst instance of abuse was once, for a couple months, I used tethering as my only home Internet access as my land lady was dragging her feet on getting Internet access installed. During one of those months I decided to watch the first few seasons of The Mentalist and that uses data plenty quick. An hour of video is still several hundred MB even with these fancy new encodings.
Their current deal is $50 for an "unlimited" plan that switches to EDGE after 500MB and $60 for a similar plan with a 2 GB limit (or 3 GB, can't remember which).
Yes, the unlimited data plan is the horseshit, despite what that playboy is telling me.
After getting throttled on day 3 of the month with my new phone, I'm down to approx 70 kbits/s. I can't even watch youtube without a 50% duty cycle.
and T-Mobile is far from sucky. I've had them for ~10 years and had numerous problems with various aspects of their company.
When I bought my last phone through them, their website failed to let me transfer my old phone number to it. Instead, it started a new account for me. Three calls to customer service and it's not resolved.
The first call the operator couldn't figure out what was going on. The second, the network quality to Asia was so bad, there was no communication possible. The third, I was hung up on while I was transferred.
Last time I filled up my monthly card, their web page said the fill up failed, so I tried again and it failed again. Next thing I knew, the charges had gone through twice.
The year before that I signed up for a data plan, but it wasn't compatible with my phone and they wouldn't cancel that plan - until I used a lawyer.
There have been many bumps in the road prior to that, too. I only use them because they have the right balance of coverage for the price. That is to say, second best coverage in my area and second highest monthly price.
There still are a lot of bumps. Their billing systems remain a mess, especially trying to use it on an iPad (if I don't disable wi-fi, it asks me for the iPad's phone number). I really wanted to use T-Mobile to support their free 200mb offer, but it's a mess to sign-up for extra data.
My final reason for leaving -- even though they suffered many high profile password hacks in the past, they still store them as clear-text and email it to you when doing a password reset.
That stinks. I had my old number changed over and active service in < 1 hour. Their service is actually really good here in atlanta other than in parking garages, and strangely, in my own domicile. I get phone reception, but no data. I have high speed internet and wifi at home though, obviously, so it doesn't matter.
My personal experience with their throttled data is that it is perfectly sufficient for emails, WhatsApp, and even low bandwidth radio and audio podcast streaming. It even works for moderate internet browsing in a pinch, although if you need more additional high speed data is still quite cheap ($10 for 2gb and $20 for unlimited).
None of the ones labelled "unlimited" look like "5GB cap", they look like unlimited on the phone + limited amount of tethered usage. It would seem to make very little sense to offer 5GB + 2.5GB for the same price as a combined total 4.5GB.
This is an off-contract pre-paid plan. I believe that you must buy these as SIM kits from Walmart. When I got it, you had to buy it from a physical store, but it looks like you can do it online now though it may take some time for your SIM card to arrive.
Word to the wise, you get basically no T-Mobile customer service once you switch to pre-paid. I have been on contract with them before and they are very helpful, but on pre-paid it seems like you are on your own.
It is worth noting, however, that T-Mobile has some serious problems. There are large swaths of this country where T-Mobile simply doesn't have service. For instance, last time I drove from Denver to Chicago I lost reception 1 hour into the trip and got it back a few hours before I arrived. There was perhaps one town where I had service during the drive. I thought that this couldn't possibly be right, but I stopped by a T-Mobile store and confirmed that this is the case. I thought that mobile providers worked to ensure that your phone would work at least when you are on an interstate, but not with T-Mobile.
Also, unlimited Internet doesn't really mean unlimited Internet in practice. They throttle so heavily after I hit my 5 GB cap that they might as well have cut off the data plan. Programs stopped working as the requests would time out and the app would assume I had no connectivity.