Which type of filament is most commonly used right now?

[Larry]

I think in general PLA has taken over. There are benefits to each, but PLA is less toxic. Which to buy? Probably depends somewhat on which 3D printer you own. Makerbot makes a great filament but you will probably spend a bitt more on it. Ninjaflex is amazing for rubber-like prints. You could probably ask this question to 100 people and get 100 different answers though Lulzbot TAZ 3D printers are known for being able to use a multitude of different filaments.

[BearsFan]

thank you Larry for your advice.