Make sure your site is agreeable, than submit it to dmoz (AKA The Open Directory). See this question as well. As far as other links go, you really do need to work for them. I suggest:
- Finding forums and adding something worth while to conversations while utilizing your signature link
- Do the same thing with blogs that match your topic. Don't SPAM, make a concerted effort to add something useful to the conversation. That generally gets your link approved, many blogs remove the 'nofollow' from posts that quality users submit.
- Go ahead and submit to the 'junk' directories. You never know, you may find a great proponent for your site by doing so. In my experience, it doesn't hurt. Just make sure the directory is moderated to a degree. If you see something like 'group sex with aliens', don't bother. Discretion is the key there. If you see a lot of broken windows in any given directory, move on.
- There's no shame in self promotion when it comes to social networks. Moderation is the key. Conduct a simple breaching experiment prior if the rules are not clear to gauge any given community. Be polite, be responsive and don't just dump links and run. Courting a community means being part of it.
- Give some thought to bringing on people who eat, sleep and breathe marketing and branding. Some things seem simple until you spend a whopping fortune only to realize that they aren't so simple. Qualified freelance talent is often affordable.
This question is kind of 'meta' in nature, hence the answers will reflect that, but I think you've touched on a good point. However, 'good sites' entirely depends on your topic, and I think a list of them would result in a rather lengthy discussion which is off topic for this site.
Note, "How do I move the turtle in LOGO" was a breaching experiment, conducted by one of the owners of Stack Overflow.