So, I want to buy some domain names and I've got quite a few options that have been emailed to me, but some that look really attractive have dashes or underscores in them, and some are not .com.

My question is directed to people who have developed sites that earn AdSense/Affiliate income, does it really matter if the domain has dashes or underscores in it? Can anyone confirm that the major SEs don't like these?

The difference between .com or .info, is it really that important? I have a budget of a couple hundred dollars to spend on one or two nice aged domains, but I can't afford to waste this, I need to know that whatever I buy is going to work for me. Thank guys, appreciate our answers in advance.