The canonicity of Asylum, Shadow Puppets, Aftermath, and Only Human are very much in debate.
My rule of thumb is that if Joss didn't have any direct creative input or oversight over something (as writer or executive producer) then it's not canon.
My list would be:
Buffy: The Origin (Comic)
Buffy the Vampire Slayer (Complete series)
Angel (Complete Series)
Tales of the Slayers (Comic)
Tales of the Vampires (Comic)
Fray (Comic)
Angel: After the Fall (Comic)
Buffy the Vampire Slayer: Season Eight (Comic)
Spike: After the Fall (Comic)
(Joss didn't co-script Spike: AtF like he did Angel: AtF... however, they are both part of the same overall "Hell-A" storyline that Lynch and Whedon created together, and I consider that entire arc to be canon as a result. It includes Angel: AtF issues 1-17, Spike: AtF miniseries, and Angel issue 23, which is an epilogue. I wouldn't argue too hard with people who want to add Asylum and Shadow Puppets to canon, since they're heavily referenced in AtF.)
The Buffy roleplaying game also included some canonical stuff from Joss... like Faith's and Kendra's last names. (Lehane and Young).
But no, the videogames are not canonical.