Sous-vide is interesting to me but only seems worth it if you eat a lot of meat. Am I mistaken?
That being said, my absolute favorite thing to prepare sous vide is carrots. Lots of other root vegetables (turnips, burdock, sunchokes, new potatoes) can similarly be cooked in a water bath to a temperature just high enough to soften them without extracting flavor or nutrients via boiling, steaming, or sautéing. I've also had good luck with green beans, asparagus, and broccoli rabe.
Finally, if you're pescetarian seafood is also a great option. I'm not sure I'll ever cook lobster any other way after seeing what whole (shell-on) lobster tails are like cooked sous vide with a healthy dollop of butter.