What CDMA companies for iPhone 4 is best?

I have a CDMA iPhone 4 and i want to know what company is best, cheap, reliable and fast in speed. Verizon is expensive and Metro is relatively slow. Please can anyone answer me prices and unlimited plans? I want to make the right choice in flashing to the right company

Verizon is best but if you want something cheaper and a good service, I would suggest you StraightTalk. $45 / month unlimited everything.

Net10 unlimited talk, text and web $50 per 30 service days. Net10 sim cards are sold at Net10sim.com for $15. Net10 airtime cards can be purchased at many retailers.

Straight Talk unlimited talk, text and web for $45 per 30 service days. Straight Talk sim cards are sold at Straighttalksim.com for $15. Straight Talk airtime cards are only sold at Wal-Mart and online at Straight Talk.com