If your budget covers it then go for Digital Nation ( http://www.digitalnation.com
). Don't waste your time searching the net for unlimited bandwidth dedicated servers, because when you do find them within a few month they will change their policy (just noticed two that were offering unlimited and have now changed). Dn is very reliable, secure and I can personally put you in touch with people that can provide references.
Communitech also provided provided dedicated servers and have some great spec machines at good prices.