#1
what is the best brand for guitar effector...? i just know 'boss' product...besides that, 'line 6'
#2
Ok, first its guitar effects, also known as stomp boxes (individual, small boxes) or multi-FX (typically large, expensive)

Boss and Digitech are the most famous effect companies.
#4
It's all opinion what brand's the best, you won't really get a straight answer for it.

I prefer Electro Harmonix, Vox and Boss.
"Breathe, breathe in the air
Don't be afraid to care"

Fender Strat/Tokai LS80>few pedals>Orange Rocker 30