1.Relevancy - Always good to get links from relevant websites.
2.Domain Age - Not really important, I prefer established sites because they tend to be less likely to go out of business and I like when my links stay alive for a good long time.
3.Google PR - Public only sees toolbar pagerank which is not the same as real PR and has many accuracy issues. Still TBPR is an easy and fast albeit inaccurate way of judging a website.
4.IP Location - Don't really care myself. If two powerful & relevant sites are on the same ip I still want links from both sites.
5.Quality of Content - I don't specifically judge content but I do avoid sites with poor experiences they are more likely to be spammy sites that get shut down.
6.User Experience - If they have a good user experience they are more likely to have real traffic and that means my link has a higher chance of getting clicked on by visitors to their site.
7.No of daily visits - More visits means more chance I get traffic from the backlink making me less dependent on Google which is a good thing.
8.No of OBLs from the page where I get a link from - Generally high amount of outbound links means it is a cheap link farm to be avoided. I can think of exceptions like a quality newspaper article on the top gadgets for the holidays and it linking out to many different store sites.
9.No of pages indexed - Personally I don't really care. Some sites have published few pages so they have low pages indexed, other site have glitches with their CMS which artificially inflates the count of pages indexed.