I think some people were put off because series 1 was a bit gross at times - I preferred it when it got into series 2, 3 and 4 but having said that, it was still compelling TV, right from the get go.
Gus was a brilliant character, as was Mike. It was an inspiration bringing those two in. I read that Truco was going to be in it for a longer duration, but the actor who played him had previous commitments, so they had to cut him out earlier than planned. I think that was a good thing, because that story arc could have gone on a bit and Truco was a truly loathesome character. It became much more interesting once Walt and Jesse had to find a better solution to distributing the meth.
I loved it - I watched the whole thing three times straight through

It's one of those shows you don't want to ever end.