1) reddit.com
2) del.icio.us
3) buzz.yahoo.com
4) stumbleupon.com
5) fark.com
6) Propeller.com

THANKS FOR THE great article, It is very true, much harder to get on the first page of digg.and its not the top 60 users who are getting at the top every time either. I would have mentioned one more site that you didnt write about, which is http://www.opentopix.com , which is growing quite fast

Thanks for the tips. I agree with Vemrion, I think Mixx should be on this list……. Also I think Diigo is pretty good as well.