I'm from Sweden and the most common way to say hi would be "hej" (hey).
Then of course you have to more casual "tja" (sha) or "tjena" (shena, with the e pronounced as the e(a) in "ear"), and "hallå", which is used for answering the phone.
Aaaaand then there's the more old fashioned greetings like
Good day - God dag
Good afternoon - God (efter)middag
Good evening - God kväll
Been lurking for some time now (mouahaha, I've got my eyes on you...), but I haven't really seen any other Swedes. Am I really the only (from now on) active Swede, or are they all just hiding? Or
maybe they went into hibernation due to the bloody cold...