@futuremrsk18: Hi, I have been to most of these places but it depends what type of holiday you enjoy and also what sort of weather you are wanting.
The places that you have chosen are really quite different. Also each are very different in price e.g. Switzerland is very expensive whereas spain is a lot cheaper in comparison.
If you want cities I think places like Prague, Krakow (poland), Budapest, Vienna, Geneva, Amsterdam, Dubrovnik and Monaco are all amazing.
I have been to Barcelona but I really don’t think that it needs more than a few days, It is beautiful there but I do think that there are nicer places to see as well if you only have 2 weeks.
I absolutely love Slovenia and Croatia, they have the most amazing scenery but are not too good in way of beaches although they do have some that are gorgeous.
Portugal, Spain and France have the best beaches and weather of the the places on your list. I recently stayed in Lagos Portugal and loved it. The best beach location in europe in my opinion is Sardinia, amazing but expensive though.
The only place that had disappointed me is Italian cities… I went to Rome and Naples there was just so much graffiti and bashed up cars everywhere. I love places in Italy like Sardinia and Lake Garda though.
Switzerland and Austria are absolurely stunning definetly go to either one of those.
If you reply with what sort of holidays you enjoy i.e. beach, lakes and mountains, warm/cold/hot and time of year e.t.C i will be able to give much better advice.
But I would be careful with your 2 weeks estimate, you should take your time to enjoy these places and not rush from one place to the next. Try go to countries that neighbour each other and if possible go for 3 weeks.