This is a bit of an odd way to look at it, but my advice is that if you watch some classics and hate them, keep on watching because each different Doctor and companion change the dynamic of the show completely. If you love the show I'd say there is no way you can get through the classics without finding a Doctor/companion pairing that you don't like. And the stories are great
As always, I find myself agreeing with Peri. I remember the first time I watched a Jon Pertwee episode after having never seen one - i thought it was unwatchable at first. Now, I gotta say that Pertwee is now one of my favourite Classic Series Doctors and Terror of the Autons one of my all time favourite episodes. Watching Classic Who is truly like watching another show - but I promise, the spirit is exactly the same