The answer to this question will depend upon what your site is about. If you have too many sections on your website then you will tend to use 3 column layout. The answer to this classic question is both layouts are good and work if you design your site well.
2 column layout:
1. Use when website has less sections. Use it with fixed width themes to give better appeal to users.
2. Generally if you have a 1028px or more width users tend to get lost when reading from left to right. So use two column with 770 px width.
MSN.com is a good example of high content , 2 column layout design.
3 column layout.







