have been with all of them at one point or another, sky tv is the best out of them for tv packages, virgin internet has been decent and the v box is a decent bit of kit, phone all three virgin ,Bt, sky and play them off against each other, just say one has offered something and can they beat it, research it on the net before you do it as they know each others basic plans.
There are other ways to watch the channels you want some not strictly legal , but you can get a setup for about £60 if you have a dish, then £25 a year,
Android boxes running kodi, like the amazon fire stick £35 or the box £70 which is better, if you put a little effort in you can get most of the stuff you need, bit up and down but if one stream isnt working there are plenty of others,
Dont fall for the hard sell in the adverts for some of these boxes i haven't seen one yet set up ,
that you cant improve yourself with 20 minutes messing about using Totalxbmc installer and pick a community build that suits you, which does all the work for you, its on youtube how to set up and use, its simple, and free.
find myself using the android box more than the satellite these days better for movies, catch up and you can get most matches .