There is none!
I use a Daisy Red Ryder BB Gun.
Marksman 1010 is the cheapest and slowest BB gun on the market.
See the link below
one that you can afford
Impossible to answer. You don't define what "best" means to you.
Go to the Google website, and from the upper toolbar select IMAGES. On the search page, enter "airsoft" or "BB gun", and you should find hundreds of pictures.
"Best" is always a personal opinion. Here is one that sells all types of air guns. See the link below
Nerf gun
If its a BB Gun, Then Yes.
You get what you pay for.
NONE! this is a pellet gun not a BB gun. Using any hard BB will ruin the rifling in the barrel and make the gun inaccurate. Read page 6 of the owners manual it tells you how to load the gun and says nothing about BB's. It should shoot pellets only.