One thing that I think sets PC games apart from their console counterparts is the ability to customize them. Older titles more often than not either came with a map or rules editor or if it didn't, someone on the internet would be clever enough to create one. So when you inevitably finish the single player campaign and tire of multiplayer, the game remains interesting due to all of the custom levels and modifications that you can either download or make yourself!

I think it's kind of a shame that the combination of complicated 3d engines and 'DLC' (I still call them 'mission packs'! :-D) means we see alot less of that with newer titles.

So what was your favourite game as far as mods and maps go? For me it was Red Alert 1 and its wonderful Rules file, which was a text file that defined every unit and structure in the game. You could create some crazy stuff just by changes a few values in that file!

I liked the Baldurs Gate mods - primarily the one that makes the two games seemless (sorry I forgot the mod name)

edit: BGT and 2nd time, easytutu

Doom and Doom II map editing is always a blast.

If Rom hacking counts, The Legend of Zelda

if not, probably Doom as I used more custom maps with it than any other game I've played.

I used to spend a lot of time creating maps in Warcraft III. Really enjoyed the editor that came with that game.

I was never a big modder, but there are some real gems made for Postal 2 . A Week in Paradise is well known, but if you dig very deep, there's some really sick stuff available for it.

DooM

Neverwinter Nights, Neverwinter Nights 2, Heroes of Might and Magic III, and SW: Knights of the Old Republic.

NWN, NWN2, and HoMM III, were all fairly easy for me to build new content with, especially new maps, campaigns, that sort of thing and download and run other people's content for new lands, etc. Personally I spent a lot of time with HoMM III, great terrain builder. Almost as fun as Sim City 2000's.

KOTOR was probably one of the games I modded most with other people's content for the base game. Not trying to make a new campaign or anything, just altering the OC to make it richer, play smoother, and have a few different plot quirks.

Does Morrowind count? You kind of have to mod it just to get it playable to begin with. Ditto with KOTOR 2, kind of.

I haven't done much modding, but I'm having a lot of fun working with the Shadowrun Returns Editor.

Worms. Custom sound sets were great, naming worms/teams was fun, but i adored drawing simple or complex levels and waging devastating wormwars in them.

Also designing missions in the old Breach 1.

Doom was great to make maps for. Even for people with no real knowledge of how to do that stuff properly (IE me). I seem to remember having a map editor that literally let you build levels by drawing squares from a top down view and then setting a ceiling height. Good times!

Really? I have a physical copy that runs perfectly on my win7 laptop. I will say any TES game always has great mods available though.

I should have qualified that, sorry. :-( What I mean is that it kind of has a shit scaling system and just seems full of bugs all around. If you play it vanilla you may not even notice but once you've patched and moded everything up you'll find yourself never wanting to go back to the original.

Your basic assessment is correct though. It should run just fine out of the box. The mods just tweek it is all, make it a little better rounded and user friendly.

Without a doubt Morrowind. Mostly just graphics enhancements and GCD. But some gameplay mods were fun also.