IMO marketing your website start with your content.  Providing useful and re
levant content in your niche is very crucial.  Here are my top 6 picks:

1. Great content - be it information, service, products... providing relevan
ce and usefulness gives you higher chances of making a visitor into a custom
er 
2. Forum and blog posting on relevant niche - you participate constructively
 and learn new things while promoting your site via signature.
3. Pay-Per-Click - done properly, best at getting target traffic faster on a
 direct marketing approach to your potential clients.
4. Targeted Link backs - another premium way of getting the right traffic an
d would help also in PR building so long as you submit to high PR sites or d
irectory
5. Article marketing - useful and relevant articles to your niche is a nice 
way of link baiting. 
6. SEO - through link building - this will get you more traffic in the long 
run 

What are your top picks?  How do you promote your sites?