Well, at least here in Spain it is much easier to practise Romanian than Korean or Hindi, and there are a lot of live speakers, although it is true that there aren't too many resources...But, there aren't so many resources for Korean or Hindi either. Maybe Czebra is planning a trip to countries where those languages are spoken and that's why he/she thinks it'll be easier to learn them.

What I meant to imply was that maybe Czebra is learning the languages in order of how much s/he likes them and wants to stop learning languages at some point. There are lots of languages I'd love to learn but at some point I'll have to stop learning new languages.

My plan is the following:

First priority:
German, English - to mother tongue level, currently - advanced
Italian - high level, currently - upper intermediate
Indonesian, Chinese, French - high level, currently lower intermediate
Japanese - upper intermediate, currently zero level
Dutch, Spanish, Portuguese, Korean, Filipino - intermediate

Second priority:
Arabic, Hindi, Thai, Vietnamese, Czech, Polish, Serbo-Croatian, Welsh etc.

Why learn a language only halfway?

Depends on your purpose of using the language.
You may want to be a translator and work with that language. Or, to discuss business or political or cultural issues at that language.
Or you may just want to travel to that country for a week or two, and you have to discuss with locals only time and place of the next party, or your special wishes for your hotel room.
Learning a language may be time consuming, so you would not want to spend some 900-1100 hours learning a language you are not actually going to use that much.

I'm learning Russian right now.
But here's my full list:

-Russian
-German
-Japanese
-Portuguese
-Arabic or Urdu

That list is order from learning first to learning last. Anyone know what Russian is like once you get in the more advanced part? And Arabic or Urdu?

Arabic and Russian are usually considered to be hard languages. Urdu somewhat less so but all of them are fairly alien to the Standard Average European paradigm.

I've studied Arabic for years and have very basic Russian and Urdu.

I'm a native speaker of English, and right now I'm trying to improve my French. I'm not sure what language I would take up next; I am think of either Spanish, Portuguese or German. I might take up Tagalog or another Filipino language, since my mother is from the Philippines (I never learned the language(s)) and she actually teaches one of the languages at a community association.

I wish I could learn several languages at the same time, but I don't think that would be really effective.

If she's from the Philippines, does she know any Spanish? That's always a good choice.

My understand is that Spanish hasn't been mandatory in Philippine schools for a century. If any of the Filipinos I've met know it, it's because they studied it here in the States. For most, the only Spanish they have is their names.