Hey everyone,
I'm just wondering which of the three packs I should buy as a total Creatures newbee? In my gaming life I've read several times about this very interestening game series but never had the money to spend or I simply forgot about it.
Is the AI any better in the newest game or are they all equal?

For a first game you'll probably want to avoid the Creatures Village pack, as that's targeted for very young children and while it is still cute and entertaining, there's not a lot of emphasis on the ALife aspect; it's more about minigames and puzzles and stuff.
There's a bit of debate over the ALife/AI in the other games. In general, the ALife in the Exodus pack is considered to be more "advanced", but some argue that it's also more pre-programmed and that the creatures do a lot of things because they are hard-coded into them and not because of the actual ALife aspect that makes Creatures so fascinating. For this reason there are a few people that still swear by Creatures 1/2 (Albian Years).
Personally, I would recommend Creatures 3/Docking Station (Exodus) because it is the most recent game and thus the one players have developed (and are still developing) the most 3rd party content for. There's also a ton of community support available for it and you're more likely to find answers to any questions you might have about it, making it a rather easy first game to get into. However, I would still recommend trying out the Albian Years pack eventually-- They're all great games, really.

Thank you for your very informative answer. I have another question:
On the Eurogamer's news according to the release of the games on gog.com someone stated the following:
Is that true? What do I have to do to avoid this bug / problem?

That was only a problem in Creatures 2, actually. The community not-so-affectionately labeled it "One Hour Stupidity Syndrome" or . But no worries, you would just have to find a 3rd party genome that addresses these issues, such as the [url=http://www.double.co.nz/creatures/norns/index.htm]Canny Norns.

Does 3 work on 64 bit systems?

I don't believe so, or at least my version won't; I have to set my settings to 16 bit before I can even launch DS. But I also have the original versions of C2 and Docking Station, so perhaps the Exodus bundle works differently.

Yes, the gog.com version does.