IMO = "In My Opinion"
I really enjoyed the return of Dr Who...it's certainly one of my favourites, but I'm not sure it's my absolute favourite (that's still probably Firefly)...then again, my opinion may change once I've watched the series a few extra times on DVD.
I think the best thing about DW is the cross-generational, cross-genre appeal; i.e. older fans, die-hard SF fans, kids, drama fans, even the people at my work who usually only watch Reality TV / Footballer's Wives were watching it.
Most importantly for me, is that my wife, who's not a huge SF fan, loved it as much as I did, which is a good thing.

)
VB
PS - but I think it's important to remember that statements like "best" and "worst" aren't really that helpful / relevant; "favourite" or "enjoyable / unenjoyable" are better ways of expressing subjective opinion... ;o)