Ok, I just finished watching the first series (I fucking hate calling it that, but I'll go with the flow), and these are my opinions.

Eccleston was a lot better than I expected.
Billie Piper is hot and not annoying.
Captain Jack was a good adition to the cast.
Didnt like the fact nearly every episode was on Earth.
The humour throughout the series was well played, without it becoming a comedy.
The villains for the most part, were good.
I now look forward to the pre-ordered series 2 (I actually pre-ordered it before I bought this series).

Now as a quick aside, we have Torchwood coming as a spin off, but wouldnt a Captain Jack spin off be pretty cool? (unless of course he is dead or something)

Snarf is shit. His death will be rejoiced!