i think the title says everything
which version do u recommend?
which one are u using?
2.49b or 2.6x?
or something in between?
i think 2.49 because i think some pro-developers are using it
correct me if im wrong
if someone made a thread like this one before pls forgive me and post a link to that thread or just say it
for game-development
I recommend and am using the latest release candidate from Blender.org - 2.64 RC2.
As far as I see, I don’t know of any ‘pro developers’. If you see some people using 2.49, it’s not because it’s somehow best for game development. It’s that people who have been making a game for a long time would rather stick with what they know than pause development for awhile to learn the new UI, hotkeys, and controls of 2.6. That might be why you see some users still using 2.49.
At the end of it, to me, 2.6x has a much more improved workflow when compared to 2.49, and it’s gotten a lot of updates and fixes (i.e. in my opinion it’s better than 2.49, which was pretty good).
All of them, and report dah Bugz
well i used 2.49 until i found that the 2.63 has some improvements that allows more stuff in the game without lagging it, it was hard to me to change, because of all the hotkeys and that stuff, but was worth the pain 
I’ve been learning Python (I’ve been through both intermediate and advanced Python courses at NCSS). I have some games running in plain Python, some using Pygame for GUI. I’m basically wanting to swat up on Blender modules so that I can get them going in full 3D. Will be using 2.6+ unless available tutorials, documentation force me to do otherwise. Using latest versions of Blender is a non-brainer IMO.
How could you ignore the Variance shadow type at this point?
To start a project it is usually a good idea to use the latest stable release. Which is currently 2.63.
The release candidates are as the name says, candidates. You can try them. You should not discover much problems.
I think that it seems that “Pro-Developers” are using version 2.49 because their games look the nicest. This is simply because they have had more time to develop the game, since 2.49 has been around longer than 2.6X
SolarLune and Monster basically covered what I was going to say.
“Professional” or not, game developers will likely only be using 2.49 because they are already familiar and comfortable with it, and just never made the transition to 2.5+. You aren’t very likely to see a new developer/3D-artist choosing to use 2.49 over the newest stable version - most of the Blender community seems to be on the latest version, and that’s where a majority of the support is at. This can apply to using Blender in general, and not just game development.
For game development involving Python, it’s even more important to consider being up-to-date with what the community is using, in order to help ensure better support. This is because the 2.5 update presented major changes to the Python API for the Game Engine.
The latest stable version will also have more updates and fixes to bugs in the previous versions, as SolarLune mentioned.