Google Chrome or Firefox.
Chrome -
1. It won't crash.
2. It's really fast.
3. You barely notice it's there. (Actual URL and bookmarks take up little room.)
4. It makes searching simpler. (Type search terms in URL bar.)
5. It gives you more control over tabs. (Easier to browse throughout, etc.)
6. It opens new doors on your home page. (Most visited, apps, bookmarks, etc.)
7. It lets you stay incognito. (For any pr0n viewing needs. )
Firefox -
1. Customization, many skins and extensions for download.
2. Firefox is compatible with everything. OSX, Windows, Linux, etc.
3. Large and useful add-on selection.
4. Fast as well. (In speed tests conducted by Lifehacker, Firefox 4 outperformed Explorer 9 in almost every category.)
5. Tab control, similar to chrome.
6. More that I cannot think of.
Firefox does look more.. in the way than chrome, though.
I personally use Chrome, it runs a bit faster than firefox in my experiences. I think that either of these, or Safari, Opera, and any other popular internet browsers are a lot better than IE.