I'm riding 32-mm slicks on my commuter. I haven't made the switch to tubeless yet, although I've considered it. Anyhow, I recommend getting fat.
Riding over patchy pavement as I do, having a larger air volume and being able to run lower pressure is really nice. If anything, I've been in the habit of running high pressure for so long that I can't get used to running pressures as low as my tires will allow.