Well, a browser based game that is considered RPG is monstersgame (
Monstersgame - EN - World 1) - may be as well available in your native tongue.
A game that I played in the past and has lots of potential is
Travian - Browser Game - Romans, Gauls & Teutons. It is kind of a mix between Asterix and AoE. Lots of fun.
Ogame is taken in very high regard, although I haven't played it. It has it's own section in gamefaqs, last time I checked, and the reviews are very positive.
eRepublik - The New World | Online Social Strategy Game seems very interesting, specially if you are into politics.
They seem to be all available in many languages (if not, then most of the games in this list), and are not like your average flash game. They are MMOs and require you to go back everyday, although many don't require that much daily time. They are not flash games, BTW.
They seem to be all free, too, which is an undeniable plus.