hello there,

i already got 3 tourist visa in my passport since last year,

is there any difficulty to get more and which neighbor country is preferable to apply for them?

the nationality of my passport is german, my self is universal....

You can obtain a TV no problem. If you have obtained previous 3 from same consulate then best obtain your next elsewhere. Many people suggest Vientiane or Penang.

A long as you have not gotten all your tourist visas from the same location you should not have a problem getting another one.

If you have not gotten all of them from Vientiane that would be a good place to get another one.