Cigars International (I buy 75% of my stuff from Joes Daily Deals) and Cigar.Com are two of my preferred places. I also like Corona Cigars out of Florida
http://www.coronacigar.com/ I have not bought a lot from them but Holts
http://www.holts.com/home.html is very good. There are just a ton of very good Cigar suppliers. JR, Taboo, and Party Place are all great too. Everybody has their favorites for one reason or another but you can't go wrong with any of those I listed just shop around them for the best price knowing they all offer excellent service.
Cheaphumidors.com offers good prices and good service, many customers in the Asylum!