I use Maptool for my gaming needs currently. Its got the most customization Token Overlay system in any VTT. But, it runs like a slug. EpicTable is the closest 2nd as far as interface, usability, and speed goes. I would love to buy it, but wouldn't do so until I could slap custom condition images onto a token at the very least. A quick show/hide from players button would be nice as well.