I moved onto Hagemony 'cause it was a lot more streamlinded than the predecessors.
If you loved IG2 for the story and the atmosphere you will love IG1.
If you're into oldies get Reunion (from HOTU) that's also one hell of a game. (Dosbox recomened for running it).
If you want something with more of strategy and less micromanagement get Haegemony along with its expansion.
The Hungarian dub for the former was really impressive - and the cutscenes are even better than the ones in IG2 - though I haven't heard the English dub.
BTW Reunion, IG1, IG2, and the Hagemony series are all Hungarian games, that's why a native dub was made.
The soundtrack of IG2 won a prize at the 2002/2003 E3 AFAI remeber, and bet some great studios with a lot more money, but less talent uder their belts.