We tried Thelonius Monkfish in Central Square recently and it wasn't half bad. I think I avoided/mentally blacked this place out when it opened due to the hideous name. We walked by a few weeks ago and thought it looked pretty good. It is always packed even on early week nights, which is at least a sign that product is turning over and relatively fresh.
We just grabbed some quick take out, a sashimi and nigiri platter and a few maki. The fish was extremely fresh, flavorful and well cut. Even the tako was tender. I didn't dislike the Temper Tantrum Maki (tuna,cucumber, scallions & chili sauce). It is certainly not traditional in the vein of Sushi Island or Toraya, and there are plenty of 'americanized' maki creations which are par for the course for most Japanese restaurants in the states (and the cause of much angst on these boards). There is also an asian fusion side of the menu. However I would have to say they offer the best fish in Cambridge (granted a low bar).
It probably didn't hurt that we went in with low expectations. I will have to visit again soon and sit at the sushi bar to give them a bit more of a try out. It wouldn't be bad having a place nearby that is at least servicable and reasonably priced.
Any other experiences with this place?