Panerais are still pretty rare in Houston, I come across maybe 1 per month in the wild.
Rolexes are everywhere, obviously. There is definitely a tradition in Houston where if you are an older gentleman who wants to tell society that you've made it, you get a yellow gold Day Date. Tons of these around. For the young professional crowd, the SS Sub is definitely the go-to watch. Which, sadly, makes me less enthusiastic about wearing it to the office. I'd say half the bankers between 25-35 walking around down in my lobby (with ties but without their jackets LOL) are wearing SS Subs. There's a huge trend among the MILFs at my club wearing Daytonas (RG or SS) and Day Dates. At any given time of day in the gym or by the pool, I bet you could find at least 2-3 ladies wearing a Daytona.
Hublots are very, very popular among the middle-eastern crowd. I don't mean any disrespect by that observation, but it's an odd trend that I've noticed.
I've only seen maybe 3 APs ever in Houston (outside of the jewelry store). In fact, most of my buddies who are huge AP fans had never actually seen a Royal Oak in person before mine. Most recently, I did see a young guy wearing a Rose Gold ROO Barrichello . . . in the gym! LOL
I never understood how people can get comfortable wearing a really nice watch to the gym. If there's every a place where you or someone else could really bang the shyt out of it with something that could really do some damage, it's the gym. Plus, there are clocks (with seconds displays) within your line of site at all times.