I don't have that much experience with it yet, but Penhaligon's Opus 1870 is very nice. You may also want to check out Comme des Garcons Wonderwood. On paper I get pure sandalwood, but I'm wearing it on my skin for the first time and am getting a lot more cedar. It is a very nice, woody scent. Only problem for me is that it's pretty under the radar...I've had it on for hours and I still get a whiff of it every now and again, but it's not particularly strong.
The last sample of Tam Dao that got had distinctly less wood and was a bit more feminine. With the scarcity and price of sandalwood it's no surprise. I'd tread carefully if buying through the mail, lest you get stuck with the reformulated version.