Need a reliable yet inexpensive broadband provider that does not requuire a contract.

What do you define as inexpensive. Virgin and Verizon have no contract plans.

I've always had more success using Sprint's evdo network than Verizon's. Being the smallest major cell provider, they make most of their money licensing out their network to smaller providers and brands like Virgin, Boost Mobile, Best Buy, etc. So, when it comes to choosing between them, it really comes down to price because the signal quality should be almost identical (not accounting for shoddy equipment).

Of these, Virgin seems to offer the best plan. $79.99 for the usb device, no contacts, $40/mo for 1 gb of downloads, $60/mo for 5gb of downloads. Also, like sprint, they offer a mobile hotspot (a wireless router so your friends/family can join in on the evdo fun) for $150.