[kurthr]

I'm surprised you didn't mention the less formal Kansai local term: "oh-KIni" おおきに: It is also used as "Thank you" in casual situations, but my understanding is that it is literally "Excuse me".

So much of proper speech is dependent on who you are with and their preferred idom. Of course formality in the case of uncertainty is usually preferred, but that can lead to both humor and embarrassment.

[glandium]

大きに (おおきに) is interestingly an abbreviated form of... 大きにありがとう (ookini arigatou), in which 大きに just means the same as とても (totemo), so "very". The equivalent in english would be to say "very much" instead of "Thank you very much".