My favorite plastic was........ well, I didn't really have one. The Dranzer blades were the ones I liked the most out of all others, so if I had a "favorite" it would have to be the whole Dranzer series.
My favorite HMS......... well, I don't have one. I didn't get any HMSs. The box was weird and different from regular blades, and I being a young kid, was scared off.
I think the main problem was the most of my launchers had broken, so I wasn't really into blading much at the time.
But, more so, I didn't even know if the HMSs had launchers or cords in them. Otherwise, I definitely would have picked a bunch up. They had them for 5 bucks each at one point.
I don't really have a favorite MFB.... yet. I only own the two that came with the Vortex Stadium, so I can't really say which was my favorite. However, based on looks, my favorites would be Thermal Pisces and Burn Pheonix [but before them Poison Serpent was by far my favorite, but these guys just knocked it out of the park].