The best sci-fi show to bite the dust because of the tv executives has to be Farscape. Brilliant show.
With regards to Angel, it kicks Buffy's arse. Especially with Amy Acker

in it. I'm going to miss watching Fred

.
It definitely had the legs for another series but the last series was pretty good. Smile Time has to be the funniest episode of Angel that I have seen. See Spike get his arse kicked by a puppet.