I hope this wasn't posted here yet: Here's a free tool that checks how many sites have linked to yours: http://tools.marketleap.com/publinkpop/
not bad, I also like Aaron Walls backlinker analyzer to actually see where the links are coming from.
Ummm... no, the first isn't better, it's just different. Yeah, great, it gives comparisons, but it also requires you to enter a code every time. I need to check a lot of sites every day, and I don't need comparisons, and I definitely don't want to be typing in codes to access it... so the one I mentioned is more useful for me. And I'm sure other people who do a lot of queries would find it more useful. Sometimes simpler can be better, depending on the circumstances. Another good one is at the link below, shows the PR of the backlinks : http://www.iwebtool.com/backlink_checker