I have the ODB and I like it a lot, it can get very nasty if it needs to.
I am considering selling it, though, as I've found something I bought that I like better; http://www.mojohandfx.com/pedals/crosstown-fuzz/
It was recommended to me, I had my doubts, but I really like it a lot. Mojo Hand FX also offers a Rook pedal which they say works good for basses.
Price-wise, they are not far off from Boss and seem to be better quality. And Mojo pedals are true bypass.
But, you can't go wrong with an ODB. And if you don't like it they're typically easy to sell.