crucial is definitely awesome when it comes to rebates
antec is pretty good also
most others are pretty sketchy. Factor in forgetting to mail it and it getting "lost" I say i do better than most -- i get roughly 80%.
To me it is a #'s game. Unless it is a high value, I just play the 80% odds I have. Hassle vs $ reward still comes out in favor of $ reward.
viva rebates i say! just know what you are getting into.