Please don't be offended, DoDo, if I jump in here. I can't myself think of a major dialectal difference in pronunciation of the "th" in "think". It's an unvoiced "th" that most English speakers pronounce in the same way (with a possible slight tendency towards an aspirate "t" in some Irish accents?)
The disassociation of spelling and pronunciation, on the other hand, there you have my sympathy. But I look at Hungarian words and your explanation of how to pronounce them and marvel... ;)
