The era I like best is from the 1st doctor through to about the time when Lela leaves. And some elements of the 7th doctor and Ace, though not that bit where he's more then an ordinary time lord but some sort of time's champion, a god, or something that they were hinting at. Jnt's era is my least favorite.
I did like 4th doctor stuff after Lela left. I liked how the 1st Romana mentioned, maybe more then once, I'm not sure, how the doctor failed his first exit exam and bearly passed his second attempt, if I recall correctly. I liked some stories of the 2nd Romana's first season, and some aspects of the 1st Romana.
As for the new series, I watched it for 2.5 seasons and gave up on it. To much of the writing I dislike. Maybe a few seasons after the current guy leaves, but the bad elements that I dislike are likely to ingrained so I may just never watch the new series again.