In my long standing Byzantium (Komenid) campaign I'm really getting bored. I'm 250 years in I think; currently it's way too easy. I have completely crippled the Seijuks having taken territory all the way east of Baghdad. I have a well developed personal demense and can muster 85k troops just by myself, not to mention the 40 vassals. I hold a ridiculous amount of king titles:
Bulgaria, Serbia, Croatia, Sicily, Africa, Egypt, Jerusalem, Syria, Mesopotamia, Armenia and Georgia.
The empire can muster 400k troops at full capacity so any opponent is a walk over. The only thing keeping me from throwing in the towel is wanting to reunify the Roman Empire. Even though it might still be a challenge it seems a little pointless since I have almost 4 x the manpower as any single opponent.
Note: I'm not a great player, not playing on the hardest difficulty and I had some good luck.