Bilter has a nice list, but there are two that I think are a bit iffy.
The Center for Science in the Public Interest is a well respected nonprofit organization that examines some of the medical claims - something like a consumer reports for medicine.
go to
www.cspinet.org/nah/04_04/heartsupplements_canada.pdf
They have a nice overview of the compounds that can help your heart (fish oil, Niacin, Psyllium or metamucil, plant sterols found in the margerines Benecol or Take Control, asprin, folic acid.) They do so by lowering your cholesterol and through other routes as well.
What doesn't work (or what has no evidence that is acceptable to a scientist)? Guggol, Isoflavones, Policosanol, Garlic, Red Yeast Rice, Tocotrienols.
Red Yeast Rice sold as Cholestin did work. That is because it was spiked with a UG version of a statin drug (smart move, but if you want that just buy a UG statin for a LOT less.) Now it is made without that and there is no research on the new, undoctored, formula. (I took it for a while.)
Most of the research on Policosinol was done by a group of researchers in Cuba; it has never been shown to provide effective results in tests in Canda, the US, Europe or Japan. And, the policosinol used in the US Supplements is DIFFERENT from what they use in Cuba. (I took this as well.)
I should add that I take the ones they suggest. I stopped Niacin b/c it is hard on the liver at those doses (2 grams per day).
Green tea is helpful in a host of ways. Drink it and take supps.
If you want to look at how your screwed up cholesterol and BP will effect your chance of kicking, go to
http://www.cspinet.org/nah/10_01/heartattack_risk.html and figure it out. It made me take gear more seriously. If you use, you should take the supps and meds so you don't lose a couple of years of life.