I would usually say Australia, but I think by the time you wanna
visit after your exams, it's the start of summer already. It still
won't be too hot, so if you don't mind 20+ degrees C, you'll be
pretty comfortable there. It only starts to get hot sometime end of
January (which I really hate).
I'm more into old buildings than nature views (my attention span is
so short that it lasts for that precious few minutes for that old
click of the camera, & I'll wanna head back into the bus if I
hafta look at nature 
). If old buildings is your style, then Melbourne is
for you 
I totally enjoyed my time as a
student there, & I would definitely wanna go back again,
particularly in Spring & Autumn, my favourite seasons.
In the evening, walking down the streets, seeing the trams pass you
by, looking at those quaint old little shops & buildings,
having coffee at a charming little cafe & watching the world go
by. Wonderful dinners in cosy restaurants (prices are VERY
reasonable & quantity + quality is great), etc.
And best of all, tucking your hand into the arm of the person you
love... Aahhhhh, sheer & utter bliss 
FeowFeow
