We recommend FireFox, which you can both read about and download here: Firefox
There are a million reasons to use it over its competitors, but the most important are that it is open source, it is free and it is far more standards compliant and feature-rich than IE.
It has enjoyed explosive growth and development - 40% of people surfing the net today are using it, compared to just 16% in 2005.
Once you have started using it, you'll start enjoying it. Then please spread the word!