"Bell sucks" - OilKiller
"I love Bell" - HOOT
It doesn't matter who you ask you are going to get a different story. Some people have had horrible times with Bell TV customer service, where most don't have an issue in the long run. I have had Bell for over a decade now and have had zero complaints, never had signal loss (in both Calgary & Victoria winters) and love their quality compared to Shaw.
Just last week I phoned Bell and they ended up giving me 20% off my bill for the next year without extending my contract or adding any new programming. Bell has the better picture quality, where Shaw has better customer service, luckily with Bell you won't have to phone customer service all that often.