In terms of manufacturing basses or in terms of offering lefty basses for sale?
For manufacturing basses, I would say Schecter.
I would have to say this because they offer most of their models left handed (even if they only offer one available color). They offer their beginner basses all the way up to their more expensive basses (think intermediate) left handed. You could say Carvin is lefty-friendly too, because they do not upcharge to build a bass lefty. I wanted to start a thread similiar to this one, naming all of the brands that offer at least ONE model of their bass left handed (and maybe offer a link or something to the manufacturers website or a dealer that sells that/those particular model(s).
As far as offering lefty basses for sale, a lot of internet companies out there offer at least a decent selection of left-handed basses. Musicians Friend and Sam Ash come to mind. My pick for offering lefty basses would probably have to be http://www.adirondackguitar.com. That is where I ordered my lefty Traben Array 5 string bass, the ONLY place I could find that offers that bass left-handed. I emailed Traben asking them which basses of theirs they offer left handed and Adirondack carries both models (I think Traben should offer more of their models lefty). Guitar Center doesn't offer shit for lefties, which to me is ridiculous. With as many companies out there that make lefty basses, GC could at least stock more than 2 Ibanez models and 1 Fender model of bass (all of which are basically beginners basses anyways).
While we're on this topic though, I'd really like to mention that I find it pretty lame that Fender does not offer their non-American P-basses in left handed...for some reason that doesn't make sense. I would love to be able to try a lefty MIM/MIJ/MIWherever Fender that is NOT a Jazz bass and doesn't cost me an arm and a leg (like some would consider the American made ones). Also, I don't like companies that refuse to offer ANY of their models left-handed. I've scoured the internet looking for basses from damn near every "major" guitar/bass company to see what everyone had to offer and its sad that so few models are offered lefty (production models, I'm not talking this custom shop stuff...). If I was made of money I wouldn't really be bitching about this because I'd just get all my basses custom anyways...ah, I can't wait to win the lottery.
