If you have LTE in your area, Verizon miff that's LTE comPatible is best, the speeds are great but you need to check if you qualify for discount, my bill comes out to $41 after taxes for 5gb a month which isn't too bad for the speed and flexibility I get with it.
You could also try a clear mifi, they sell them in best buy, and they're the same price but run on wimax and offer unlimited plans.
T-mobile, sprint, and AT&T also have mifi's but I belive the monthly plans are more expensive but do give you more data. Also I wouldnt do any 3G mifi's from a cmda carrier (sprint, Verizon, virgin) because their 3G is just too slow. Anything 4g is fine, and 3G from AT&T or t-mobile is good too.