You didn't say the sound you want, but for metal there are only 2 REALLY good basses that I will reccomend:
Rickenbacker
Pbass
Those are the 2 most commonly reccomended for metal in any thread I have read about this on this site, and also the 2 types of basses I own, so I am speaking from firsthand experience with both. Rickenbacker is punchy and thick sounding, really great with fuzz or overdrive (think Cliff Burton, Lemmy Kilmister, or that guy from TOOL). Pbass is more twangy (with the tone knob rolled up high)... think Frank Bello (he played a P/J), or Steve Harris.
Between those basses it really depends on what sound you like- thick and punchy, or high and twangy. I like my cheapy Pbass enough that I plan on buying a Fender Pbass as my next bass, but I prefer the thick midrangey sound of my Ric just as much, if not more than the Pbass sound.