Hm. Buckhead/Chamblee/Doraville has a lot of Bloods (since Katrina ... pre-Katrina was more Crips than Bloods) and HOLY ---- TON of La Raza (a latino gang). Bloods tend to walk around and sell various chemicals, while La Raza like to break into cars and spraypaint LRZ everywhere. I've befriended members of both and they're nice people ... I'm serious. I guess it depends on the situation you meet them in. I tend to not be in a threatening position towards them ... they all know how us skaters/punks think and know we don't give half a ---- about what goes on. White belts. Don't wear white belts.
About 2/3 the way up 400 from the junction of 85/400 is generally Black Mafia territory. They all drive nice cars and wear flashy jewelry (real) and control the cocaine market. A lot of the higher-ups were arrested a few years ago. Think Young Jeezy.
Other parts of the city you'll find a lot of localized gangs. Same in Wesley Chapel (just east of 285 on I-20)
If I recall my old Crip friend telling me, they get along with La Raza, but I find a lot of people are more rivals with other people than other gangs nowadays ... at least in my hood. That's the exception, not the rule ... My Blood friend doesn't usually talk about such matters ... the only reason I know he's a Blood is because he's told me and he has a few tattoos.
Graffiti crews are also legally gangs, so I can go into those, too ...
Good:
Everyone besides GAC
Bad:
GAC ( they've struck a ton of graffiti crews the wrong way and recently two of them got their asses kicked ... )