I recently put in Avant Browser, and I'm really pleased with it. It's a light weight program. And you can even run it with minimized and go play a game. I have an older machine and it does really well with it. The one thing I like about it is that it has an Ad Blocker. Not just a pop up blocker. This site has quite a bit of ads and it blocks them all and makes the site better navigatible and speeds up page load times drastically.
Here's the link if you want to check it out
http://www.avantbrowser.com/
They put out another similar browser called Orca. But it's a heavier use program. I didn't care for it. Avant is the better of the two.
I also like Flock alot too but it uses alot of resources to run it.