I am a fan of AMD, mostly because my first build was an Athlon 64. Back then, AMD offered a little better performance than Intel, and they were actually cheaper as well, giving tremendous overall price/performance.
Since the Athlon 64 days, AMD has not held the edge in raw performance, but they have done very well for themselves when it comes to price/performance. In my opinion (and many others), this ended when Intel released Sandy Bridge and AMD failed to deliver on Bulldozer. The price/performance is no longer there, and Intel is currently the king of this, as well as currently holding the raw performance crown by a LOT. From top to bottom, there is virtually no reason to go AMD whatsoever.
I'm no expert, but I see two VERY select niches in which going AMD would be viable. The first is with an 8-"core" Bulldozer, for someone who actually needs all 8 of those threads at a cheaper price, but also doesn't care for or can afford a server-type cpu. The second niche is for people who want a cheap htpc or a very cheap desktop period, and in that case the APUs become viable. Other than that...nada. The only other possible outside shot is someone who can find a Phenom 2 (or just goes with a 1060T) because it is enough per-core power for them, they want more than a dual-core, and it would be cheaper than going Intel when counting in the price of the motherboard.
In my opinion, AMD has great potential in the mobile market going forward, but their current desktop offerings get absolutely destroyed in every single conceivable way by Intel, for the vast majority of users. It is what it is.
From an AMD fan that had high hopes for Bulldozer, anyone who's still saying AMD is viable in the desktop market is simply trying to make themselves feel better.