I used to use a Korg Pandora PX5D. It was fun because you can mess around with amp simulators and effects, but now I own a 3 Leaf Audio Enabler. http://www.3leafaudio.com/2012/05/24...headphone-amp/
It doesn't do the simulations or effects, but it sounds so much more cleaner with the added benefit of being a DI and EQ. You can plug it in straight to a PA if you want. Plus the builder is a member here on TB
Also the input jack of the korg started to crap out. Kind of a known issue.