Another reason why many of us keep playing Civ IV after 10 years is because of the great mods.
No!!! Lol. The game is still awesome due to it's strategical depth, mechanics, and overall game balance!
Anygame that provides that is good in my books! I'd be more than happy playing with leaders called Leader 1, Leader 2, Leader 3, so on and so forth. Hell, Keeblar Elves that breathe fire and destroy Tanks would be fine as long as depth, strategy, and balance were maintained.
Maybe I'm a weirdo ^^. I hate playing with Mods. The final game passes or fails, period. Besides, playing mostly HoF Mods are disallowed. I don't consider Bat/Bull/Bug/BlueMarble etc a Mod. They simply give you all the information you're already entitled to in a quick and easy format.
And just to throw out there, I don't play Civ IV due to it's realistic, Historic, or immersive gameplay either. You could have all those elements in a game but the game could "play" as the worst game ever produced. So yeah, those are all meaningless and have zero impact on how enjoyable a game actually is.
Civ IV its by far and away one of the most intricate building games ever made. Throw all the game aspects together and you could play the same map over 1000 times and have 1000 different outcomes. How cool is that?!