We all chase "Fools Gold" or rather "Fools Green" which is the green juice bar on broswers indicating Toobar PR. What other factors affect the quailty of the link? I'll start us off by mentioning a few. Crack this and your will get the serps you desire. For example The age of the website linking to you If it is Dmoz The page title The content Where it's links are coming from How often it's content is up dated. What ones have I missed?
You could add: -- How many other links are on the origination page -- Whether the link is direct or indirect -- Whether the link is dofollow or nofollow