I recently found Enterprise the best deal but their pricing varies by depot, day and demand so it helps if you can be flexible about the day you want the van for etc, Their daily Excess protection is horrendous at £20 a day and it is much cheaper to take a months Excess protection bought online if hiring for more than a couple of days, but for one day it is probably not worth the hassle. I hired from here in Exeter for 4 days mid week to shift stuff from Gatwick to Nottingham which was half the price of hiring from Gatwick/Crawley. From what I remember the hire rate was less than £40 a day for a 19m3 transit (ie extra LWB high top).