kind of subjective, since speed depends heavily on which cellular technology your looking at (GSM or CDMA), network infrastructure, network load, bandwidth....etc. there are theoretical maximums for each level, which the end user likely will never see. there are too many variables to consider. your data speeds may be different than mine. i can give you an idea from experience, but they will be vague and general.
when i had AT&T
EDGE: .75-1.5 mbps
3G: 1- 5 mbps
H+: 3-14 mbps
LTE: 10-???
Verizon CDMA
1XRTT: <1 mbps
3G: 1-3 mbps
LTE: 15-30+ mbps