I enjoyed playing a fighter/thief in Morrowind because it seemed to open up so much more (literally), but I must say I enjoy the way my character looks in heavy armor. The game really demands a second playthrough. Then probably back to the main quest for a while, or do the Knights of the Nine, as I doubt I'll be very successful in the Thieves or Mages Guild. I'm thinking it'll probably make sense to become a Fighters Guild champion first and then hit the arena. I've only done a small bit of exploring so far, and I haven't even seen the Arena. It was around this point that I just started exploring and unlocking the map. By this point in Morrowind, I was mostly through both the Fighters Guild and Thieves Guild line (I was doing them simultaneously), and a good way into the main quest.

To be frank, I'm surprised at how much time I have in and how little I've actually done. I'll probably do it after I finish the main quest, if it's still an option. I didn't want to spoil anything reading a walkthrough. Thanks for the advice on the tone/theme of the line.

Thieves guild or dark brotherhood first