In addition.. so long gotta run, later farewell good day/night night- night (for kids and lovers before they went to sleep) till tomorrow talk you you later or just for fun you can say it in another languages adieu au revoir ciao bis dann .. and so on.

till next time.. got to go.. see you around.. i have to leave..

do not forget: let's stay friends. Hasta la vista. f*** off in internet speaking you may encounter bb - bye bye :D

in nz we have lots of slang: laters chur you could also say: laters co/bro/cuz but besides nz slang, you could say: see ya(very common) but other than that and what you said, there are no other common ways to say it...only formal:(

Cheerio m'dear!