I have two dream campaigns: One has already been well described by others on here, the gritty urban Thieves World-type campaign.
The other would be a nobles campaign, set amongst rival noble houses (or even merchant houses, if the merchants were the nobility). Lots of intrigue, even swashbuckling adventure, and a good mix of combat, problem-solving, and interacting with other PCs and NPCs.
But either campaign needs to have a good, far-reaching story arc and well-developed characters.
The other would be a nobles campaign, set amongst rival noble houses (or even merchant houses, if the merchants were the nobility). Lots of intrigue, even swashbuckling adventure, and a good mix of combat, problem-solving, and interacting with other PCs and NPCs.
But either campaign needs to have a good, far-reaching story arc and well-developed characters.