I would say the Treasure Room glitch is the best for E-tech. I don't really care for them though. I did the glitch many times, and I only got one legendary weapon, but a lot of E-tech. --- The Princess is in another Castle. Punching trees gives me wood.
Treasure room is basically all e-tech, but I've gotten most of my legendaries there as well. Had 2 drop in the same run. Today tho I've done it like 10 or so times with no legendaries. I don't even pick up e-tech unless its a plasma caster. --- ___ GC: Rayden1898