Age of wonders is most similar to Master of Magic, it's kind of similar to Warlords but with more elements, i don't know Disciples so on that i can't comment, but if you like Master of Magic, Warlords and Heroes of Might and Magic i think you will like Age of Wonders also.

Age of Wonders 2 and Age of Wonders: Shadow Magic are much better than the first one (which is still a good game in it's own right).

And in beetween these two ones I see no reason not to for SM anway (maybe except your are into the original campaign) - it offers 3 more races, better AI and a lot of stuff more over vanilla AoW2. Plus that there is a fanpatch (1.4), with another version still in development (1.5)

Age of Wonders is Warlords 2 Deluxe with tactical combat, build-able buildings in cities and magic that can be used both in combat and on the overhead map (Global Spells.).
It also have customizable hero units and leader (You the player.). There is a debate about which is better, Age of Wonders or Age of Wonders: Shadow Magic, that resurface now and then.
The result is usually that Age of Wonders have a better atmosphere and campaign while Age of Wonders: Shadow Magic more features and is better balanced. But that is also disputed. :P

Myself I've been playing my campaign again and spent about 10 hours in one level, almost non-stop. Had to sleep though. It's a lot of fun.

Thanks for answers!
It looks like I should try :)

Fun that you'll leaning towards trying it. It's a very good game series if you like the genre and Age of Wonders is one of my personal favourites. It just hits all of my Fantasy turnbased buttons. :)

Age of Wonders 1 has such a mood that sets in. You can just daydream while listening to the beautiful music. I've been listening to it for years and years yet I never get enough of it.

Yeah. Me too. The music is amazing. :)