[quillford]

Filament quality can make a huge difference. We use atomic filament (atomicfilament.com). The owner of atomic spends a lot of time tuning his line (he recently got +/-0.01mm on his 2.85mm). It's the best stuff I've found for the price - it just prints, no clogs or anything. He also gives a discount to memebers of the reprap irc channel in freenode. As for materials, we use pla and petg.