I will stick up for Fasthosts a bit - I have been with them since the days of UKReg and VPS was just but a distant twinkle in the eye of a engineer somewhere in the world. To be clear, my domains have always been with them but hosting has been around a bit - GoDaddy, Heart, 1&1, Webfusion (before they got bought) , Rackspace and even co-location. I wouldn't say that they (FH) are really any worse than any other large host. All have their unique T&Cs, 1&1 even made you fax them to leave back in the day.
When it comes to down time (at least on the VPS platform), I haven't had any issues for the year (or near enough) that I have had some VPS servers with them. Rackspace though, I had several times of downtime and they are really supposed to be one of the best.
I guess in the end it is all down to personal experience - most are fine with their host but there is always a number who aren't - no difference to anything else really - cars, new houses, phones, etc.
No-one can really be the best - those that have the best spec will have the higher prices so in other peoples eyes, won't be the best.