I second the recommendation for Mozilla Firefox
Plus, I would recommend the following free extensions
Quicknote (it does the same as evernote I think, it automatically loads the highlighted text, automatically saves, and automatically remembers the location of the original source. It's such a simple tool, I never thought I would use it, but I'm using it all the time)
ContextSearch (it allows you to highlight and right-click the text you want so you can automatically load it into your favorite search engine(s) or dictionary through the context menu)
SpellBound (it popups a spell checker and loads the text by right-clicking on the text you want to check)
And of course, these are not extensions, but I would recommend that anyone using FireFox learn to use its mouse gestures -- they're awesome.