My favourite Doctor personally would have to be Christopher Ecclestone.
My favourite companion however is trickier. I would like to say Billie Piper as Rose Tyler, but despite it being a more silly act, I quite enjoyed Catherine Tate as Donna Noble.
My least favourite is probably the Ponds, or atleast Amy Pond.
That's perfect reason
No it's not.
For starters, many old episodes of Doctor Who aren't even widely available without doing some extensive tracking down.
There are numerous episodes that are known to no longer exist at all, as the BBC often wiped old copies or destroyed them or they weren't stored well.
Then consider the fact that you're claiming someone's opinion isn't credible because they haven't watched 40 years worth of Doctor Who.
It's like saying you can't enjoy any Star Trek things at all if you've never watched every single episode of the original series. (Which some ridiculous fans do say)
Doctor Who is just as good now as it was then and watching it now will make you feel the same way it did then.
Just because the latest ones are new and obviously have more money and time put into them, it doesn't make them less "Doctor Who"-ey and it doesn't mean you have no say if you've only seen these or enjoy these.
I've watched some older episodes of Doctor Who from various periods, including restored/reclaimed copies of some of the stories with the first doctor.
They're not super-amazing. They're very much still Doctor Who, but I'd still put my favourites as being those that have been created since 2005.
