Half of Unova's cities certainly qualify, especially in BW1 where you just go from town to town, get their Gym Badge, and you're done, on to the next town. I'd have to say Mistralton, Lacunosa, and Lentimas are the most boring in my opinion. But there's one that's more boring than any of them: being Anville Town, where there's basically NOTHING to do there at all, in fact, there wasn't even a point for the place to even exist.
The second town in each game but Gen 1 qualifies as well: Cherrygrove, Oldale, Accumula, and Aquacorde all basically have nothing to do in them at all, since the only point they serve is to basically have a checkpoint between the starting town and the first gym, as well as to introduce the player to Pokemon Centers and occasionally the first rival battle.