I used to love the very first original Settlers so I assume the earliest one here would be a good one for that ?

Also what would be the next best one to buy ?

If you loved the original, definitely get Settlers 2 Gold.

3 onwards change the game mechanics a lot. They are decent too, but different.

Settlers 2 10th Anniversary edition, is a remake of 2 using 3D graphics, with minor gameplay changes. Still, if you're a fan of 1, I'd suggest getting the original 2 first.

OK thanks :)

I would recommend you The Settlers 2 Gold Edition too. If you like it go for the remake (Settlers 2 10th Anniversary Edition). But be aware that the addon isn't available in english language. I would recommend you the 2nd remake of The Settlers II too but it is only available in german (The Settlers: Rise of Cultures).

You can however install the German vikings addon on the English main game and use fan made translations.
http://forums.ubi.com/showthread.php/203258-Vikings-add-on-How-to-Install-Play-on-English-Version?p=1832447&viewfull=1#post1832447

but you have to get hold of the German addon ofcourse...

Thanks for the information. Didn't know this because I'm from Germany and I bought the Gold Edtion long time ago. Buying only the addon is really expensive. You should go for the Gold Edition instead (base game and addon for about 8,99€ +/- on Amazon.de for example).