I've looked very deeply into all the aforementioned companies, bad reviews for all of them. I ended up signing up with a company I had never heard of (IDNet). They are the most reliable ISP I have ever used (and I've been with Freeserve AKA Wanadoo AKA Orange, BT and AOL). Sure I've never used Plusnet or companies like that but I've read bad things about them. IDNet give you free webspace, a free photo gallery and a free blog, and a free backup dial up number with your internet. They also give you several (unlimited?) free email addresses with web access. My speeds are currently at my line's absolute maximum (8mbps, I had tests done and I physically can't get more) but they also now do 40mbps fibre optic internet. I had an issue which turned out to be with BT, but I called IDNet on a Sunday morning (7am), nobody was in yet so I left a message. Just before 8 one of their staff called me back. You don't get service like that, their support line isn't automated - you get through to someone in the UK.
I don't work for them, I was a long suffering victim of AOL (Always Off-Line) and having working broadband after that is a godsend.
Seriously, give them a try or at least go to their website. They are relatively pricy but you get what you pay for!