Question: I'm new here and I saw one can buy them e.g. in Germany at bitcoin.de via an online transaction, by paying Euros. Is the same possible in Romania (do you need a €-bank account for that?) and if so, is there some (online) exchange service best suited for that?

Answer: 
There are no exchanges yet that accept RON (Romanian Leu). 

There are individuals in Romania who trade bitcoins for face-to-face cash trade:

* <https://localbitcoins.com/country/RO> <-- But be careful of the listings who are not local, wanting to trade online instead.

Also there is the #Bitcoin-otc marketplace and the #bitcoin-otc-eu IRC channel in which you might find someone willing to trade.

If you have access to purchase UKash vouchers with cash, there are several services such as Mercabit.eu, VirWoX, and Bitcoin Nordic who will accept that voucher for the purchase of Bitcoins.

Otherwise, if you have the ability to send a SEPA transfer, there are many exchanges you can use, include BITSTAMP:

* <http://en.bitcoin.it/wiki/Buying_bitcoins>
You can check out a list of exchanges that accept customers from Romania over here: <https://bitcoinnews.ro/cumpara-bitcoin> 

If I remember correctly there's one international exchange that accepts RON as well and that's LakeBTC. I haven't seen any reviews of it though so use with caution.