Both the options have their own charm - an Asian trip will show you a cultural diversity in tropical chaotic conditions, while a European trip will give you a glimpse of a very organized and well kept world. Also, budget should also be a consideration. Europe trip would be a bit more expensive.
Hey this time totally depends in what your interests and likings are and also your budget. South East Asia is very beautiful and budget friendly. Europe is mesmerising and has stunning landscapes but it's costwise higher than southeast Asian countries but worth the money spent! it's upto you ultimately to decide what suits you.
Certainly a European trip to Prague,Berlin and Amsterdam.
Prague is the cheapest of the 3 cities.Amsterdam is also small but beautiful.
In total it would require a maximum of 6-7 days for you to cover the 3 cities.