I usually use Dollar, but as this was just a short trip I chose the cheapest who happened to be Alamo. Nice guy on the desk - didn't try and sell us any 'extras' - got the necessary paperwork done in a couple of minutes. Also - and the main point coming off a 9 hour flight - no queues!
Good choice of cars - only complaint (which I think applies to ALL car rental companies) the windows were filthy - inside especially!