I love Fat Tire. My guess is that people that don't like it just aren't a fan of that style. It is an amber ale that doesn't have the hop presence that a lot of American ambers have. Somebody mentioned that it might be too bready. I think it's just right. The truth is Fat Tire is a great beer, but some people just simply don't like it.
The Red Hoptober has been a bit inconsistent, but maybe that is to be expected for the first year of a seasonal release. I have had a couple bottles that had great fresh hop aroma and flavor and were really enjoyable. And then I've had a couple that didn't seem to have much hop character at all, and seemed boring and bland. Maybe it was inconsistency in how the beers were handled. I have a hard time believing is was inconsistency in the brewing/packaging process (NB is huge and thoroughly automated). I have bought some at nice bottle shops and others at Kroger, so I'm sure there is some variance in handling and storage between those.
I'd definitely recommend trying out the Shift pale lager. It is a light lager with almost IPA level hop aroma and flavor. When I first tried it, I couldn't think of anything else I'd had that was similar.
Also, I got lucky and went to a store with an already great beer selection the day after New Belgium's Michigan launch day. They had a couple from the Lips of Faith series. I picked up the Super IPA, which was a collaboration with Alpine Beer Co. out in California. I would rank it right up there with all of the great double IPAs I've tried.
I also picked up a bottle of their Biere de Mars, which I'm going to let age for a few more months, because of the Brettanomyces added at bottling.
One other I'd recommend for anybody interested in Brett beers is a collaboration between New Belgium and Brewery Vivant (out of Grand Rapids). It is called Escoffier Bretta Ale. I bought a 4-pack (16 oz. cans) and drank one. It blew me away. I'm going to age the others and try them at various intervals of time. The side of the can says to age for up to 5 years. The few beers I've tried from Brewery Vivant have been amazing. They are definitely not cheap though (anywhere up to $16 or more for a 4-pack).