Let's not forget Slovenia. Almost all the landscape one could possibly ask for, minus glaciers, plus old castles and fortifications. Friendly, laid-back people, low prices. English spoken passably.
No experience with Serbia or Croatia, but Jakov assures me these are nice too. Montenegro is very charming but language again, like the Baltic region, can be an issue.
The Czech Republic and Slovakia are also within reach. You can do pretty well using English there.
Austria and Switzerland => Alps and lots of nature.
Thus, even within a small continent such as Europe, the potential list of venues is very long.