Yes it's regualr, but japanese as spoken by Japanese people is very contextual -- meaning that people when speaking will leave things out and just sort of expect you to know what's going on. There are different ways to speak Japanese if you are a girl or a boy, high ranking or low, and then it will depend on who you are speaking to as well. The idea of changing your numbers based on what you are counting is pants on head retarded, and the particals are confusing as hell. But yeah, logical and easy for nonspeakers to follow -- if by follow you mean watching tenticle porn in the original Japanese language.
Chinese is pretty simple to follow, though again you have the numbers varying by what you are counting, though it's usually a question of adding a word after the number, which is better, though I don't see the need.
I'd say Chinese, Danish, English, Spanish or Italian, French, Japanese, Korean, German, Latin, Greek, Russian, and beyond that, don't bother, it's not logical.
But of inventeds, I'd say Glossa, Lojban and last but not least Esperanto.