For me, Pullman has been the most reliable and consistent brand. Yes, some Pullmans lack "character." But it seems I almost always get what I pay for: efficient service, decent business amenities, comfortable bed, etc. I'm not saying I was never disappointed. I was, e.g., I had a slightly worn bed once or twice. Overall, though, I feel they're really good at getting the "basics" right.
On the other hand, my experience with Sofitel has been more of a mixed bag. I've been to very nice ones, with excellent club lounges, great service, and nice rooms, but to some really poor ones as well. A few of the negative examples that spring to mind: 1.) Rooms in dire need of renovation, ugly lobby and poor-quality breakfast at Sofitel Wroclaw; 2.) Lounge access not granted as Platinum at Sofitel Berlin Kudamm; 3.) Didn't receive a room upgrade at Sofitel Sopot (twice!); 4.) Lack of status recognition at Sofitel New York.
Generally speaking, I like Novotels. I find the brand's positioning to be useful to me. Quite a few times, a nice and new Novotel met the price point which my travel expenses department provided. And I usually get good value for the money.