What would the ideal link look like? Following is a VERY good (re-edited) excerpt i found from someone looking to outsource their SEO on www.e-lance.com.

The ideal link would be:

1. A Link from a topicaly relevant site
2. Static & Permanent One way link
3. Link should not be located on a page with more than 20 outbound links (this diminishes the PR spread)
4. Link page is cached on a regular basis
5. Link should include the target keywords and or key phrases as a title tag on the text hyper-link. Ideally link would be followed by description of text.
6. NO RelNoFollow (rel="nofollow") links in the code.
7. Link should not be through a JavaScript and or a redirect script.
8. Link should not be on Flash sites or pages.
9. Link should not be listed on drug, porn, illegal and other offensive websites (spam, ban, or blacklisted).
10. Link should not be on a page that is disallowed by robots.txt tag.
11. No framed pages, as the bots have trouble reading these.
12. Link must be in text, no graphics.
13. Link should not be posted and or participate web directory or in any commercial link exchange programs/ web rings/ link farms/ exchange programs. i.e linkpartners.com.

Hope this helps in your SEO efforts!