For me, it's the ridiculously-expensive-but-totally-worth-it pair of Outlier OG Pants. Being able to hop into a pair of nice slacks that stretch, wick sweat, and repel water/dirt/stains has been awesome. I rode through a heavy rain, had a little moisture on my thighs, but was totally dry within 15 minutes. I spent the rest of the day lecturing to my students but still looking professional. I know, I could just get rain pants for when I think it's going to rain and then change into cheap slacks at work and yadda yadda, but it's just easier to wear the same thing to work and at work--and it's great knowing that if there's an unexpected shower that I'll still be fine.