I'm paying $80/mo for unlimited voice and 5gigs/mo of data.  If I blow out that 5gigs they slow me down to "EDGE/2G" speeds which still isn't half bad - closer to 128k as opposed to 56, still usable.

I walked into that deal already owning a phone.  My latest phone is an Android 2.3 "MyTouch 4G" (HTC Glacier) which is fairly easy to root/mod and is otherwise a pretty good phone.  4G data is fast enough to live-stream video and audio to a server in Sweden which is kinda my "killer app" for it :).  See also this site for my latest capture:

 http://www.pixiq.com/article/arizona-election-officials-call-cops-on-man-recording-them

I paid $100 for that phone used, cash, at a pawn shop.

I could have paid $60/mo for their current cheapest Android 4G phone but then I'd also pay $15/mo extra on my bill for TWO YEARS, which comes to $460 total with a big up-front tax.  Oh hell no - cruise Craigslist, pawn shops, etc :).

So far as I know, only Tmobile will knock huge amounts off the bill if you walk in with a phone in hand.

Their 4G coverage area is also very good.  They're not as fast as AT&T, Verizon or Sprint "LTE" coverage, but they're still damned good.  What they've done is, they bumped up their older 3G system (HPSA) with HPSA+ to call it 4G and it really is a speed bump.  But better yet, as they roll out new HPSA+ towers the HPSA 3G devices are also supported so they're the only ones out there increasing their 3G coverage areas.  And Tmobile's 3G data doesn't really suck either - you get typically 1.25mb/s inbound, 250-300k outbound which is fine unless you need to stream-upload video like I do.  You can grab 3G Android devices for a song if you look around.

Their 4G is for me is usually 4mb/s or so inbound, a bit above 1mb/s outbound.

Jim