I tend to buy cheap, and for that the Aussie products are hard to beat. Clocktower is a sweet, clean option in the $10 range. (Preacherman's KVW suggestion is also nice for the price). Under $20, Graham's Six Grape, Fonseca Bin 27, and Warre's Warrior are reliable. Usually any of the Portugese house names will satisfy if you want to spend more. For something different, Stone Hill winery in Missouri uses Norton grapes for a vintage port that's very nice.
I've developed a preference for tawny over ruby as well, the additional complexity of wood aging adds a lot of character. Then again, I've also recently rediscovered Pedro Ximenes style sherries.