You know, contrary to most people it would seem... I actually find VV1 to be the most 're-playable'!
I've played all of them countless times, started lots of tribes - I love all the games. But I do find I can come back and start VV1 and it's the most enjoyable.
The reason I can come up with is it's the most challenging, especially on hard mode. With VV1 there's always the possibility you won't make it, but I've found with 2 and 3 the majority of times all your original villagers survive. It's mostly because of stews and potions - even if you populate a ridiculous amount, you can keep them all alive with strategic feeding of the right herbs.
I think that the uncertainty and struggle is what makes VV1 so enjoyable as a game - sometimes it feels that 2 and 3 play themselves a little bit.
So my advice is make up your own mind...if you like VV2 and 3 then stick to them, but if you want something similar but a bit different then get VV1!