For
GW you want a
GW account. Quicker access to new product, and a better discount.
For
MTG you want an account with WOTC as well as two other distributors
For wargaming figures, paints, and lots of stuff you won't find elsewhere: E-figures.com Very good guys.
For general boardgames,
CCG, and nearly everything else:
Alliance Games Distributing
ACD Distribution
PHD Distribution
The above are all who I use. Don't use Diamond unless you want to carry comics.
Other distributors.
Southern Hobby
GTS
Automatically Appended Next Post: I recommend any game store to have:
Direct accounts with WOTC and
GW
E-figures
Two of: Alliance,
ACD, PHD, Souther,
GTS. Alliance also has some things only they sell, like Heroclix.
Golden i don't recommend, always out of what you need. Reasons for that. Same with CMON. They have all the stuff that isn't hot, none of what you need.
If you sell Flames of War/Team Yankee get an account with Battlefront.
There are also contracts you must sign with Mayfair, ANA, and a couple other manufacturers to sell their stuff. Your Distributor can help.
Join this facebook group, and ask questions:
https://www.facebook.com/groups/openinggamestore/