[Rebelgecko]

Their ambi mice are decent. I use a G300S at work, and I think they have some fancier mice that are also ambi while having features like wireless charging and the toggle for smooth/ratcheted scrolling.

The only company I know of that makes an actually left handed mouse is Razer. Decent hardware, but if you're on a Mac their drivers are even worse than Logitech's. There's nothing worse than having your mouse stop working because the internet is down.

[jmiserez]

Evoluent sells a left-handed variant of their popular vertical mouse. Doesn't have smooth scrolling though.