Quite good prices [I'm still on £19.99 package :o( ], Quite good tech support [online] and decent speed if you're going for a broadband package. click here
Reliability - they're not always perfect, they are good most of the time, but some weekends (usually Sunday's) they'll have problems such as faulty equipment and this could become quite frequent at times (I guess they just have a bad month?).
The last time I had a connection issue was December 04, something went wrong on 3 consecutive Sundays, but all seems to be working now :o). A good thing about it's BB is that there are no limits.
Another ISP to consider: click here which I'm considering switching to.