If you want to run a forum smoothly then you have to go for Dedicated Server. Hosting Packages are not suitable for running a forum. But if you are running your forum on Dedicated server and having the page loading problem then you should of course change your host. I would suggest you to use xtraorbit
I have used lots of hosting companies out there. Hostgator, bluehost & hostmonster, godaddy, fatcow, dreamhost, 1and1, justhost, softlayer (former theplanet), singlehop and few more. softlayer (former theplanet), singlehop are not for shared hosting though. In terms of shared hosting, hostgator is the best solution I have ever used. If you had not use both hostgator and other hosting, you will not understand the difference. I am with hostgator for 4 years now (for shared & reseller purpose).