I've used Carmel, Dial7, Planet Limo, Allstate Limo, and a couple others, all at least 3 times. Honestly, I prefer Planet Limo. They have a decent new app, they finally have receipts online (although it takes a week), and they also seem to have better customer service of late. The drivers also show up on site typically 10 minutes before scheduled pick-up time and don't start the "waiting" clock until the appointed time.

Carmel is a GIANT pain to deal with. I'm required to submit expense receipts and they are impossible to get a hold of and even when you do, they never send you a copy of your receipt. After 3 straight times, I quit them.

Allstate is just pricier than the others and REALLY stingy on the waiting time.

Dial7 had inconsistent customer service/receipt delivery and their drivers tend to be right on time or late.

Uber Black is good from the perspective that they are insured livery drivers, but man are they pricey. Lyft drivers are generally not insured, so a bit riskier, but that's what keeps the overhead and prices low.

EDIT: Master limo/car service thread.
http://www.flyertalk.com/forum/new-y...-services.html