Favourite Dr Who doctors, in order:

• Seventh Doctor - This doctor was dark, plotting, and manipulative, but all as part of plans for the greater good. His frustrations when his plans didn't go right, the tensions caused whether they went right or not, and the struggles between his personality and the needs of the situation were interesting to watch. He represented the best of the mature series.
• First Doctor - The first doctor's universe was a lot less mallable than those in the later series, as it worked more with the you-can't-change-it idea of time travel, with situations they had to simply weather rather than become an active player to survive. The first doctor was similar to the seventh in that he knew none of his companions had the capacity to understand situations as he did, but he treated them more like a protective parent than pawns.
• Sixth Doctor - Had much of the same attitude the first doctor had towards companions (possibly moreso) and a half-mocking infinite confidence in his own abilities. Many of his episodes dealt with criticisms of character faults in individuals and societies. This continued into the seventh doctor in a more mature fashion.
• Second Doctor - Took the first doctor's role, but changed the relationships with companions to more one of an exasperated parent with rebellious teenagers. A number of interesting eccentricities came out in this "parent" as well, making him less of a reliable compass.
• Fourth Doctor - His ethical dilemmas were interesting, as were his self-doubts. This doctor was more in touch with "his people" than any of the rest, and felt a bit more alien.
• Fifth Doctor - Vulnerable, a bit like a wandering professor. Not very interesting.
• Third Doctor - Not that great - closer to being James Bond-ish than anything else. The series didn't feel as sci-fi under this doctor.

I don't consider either the Fox movie or the remake series to be properly Dr Who. They reorient the series too strongly in the direction of being action-scifi, create tension and interestingness through a much more clumsy hand (let's eliminate all the other pesky people of his race because orphans are more dramatic), suddenly make romance a constant and blatant part of his interaction with companions, etc etc. The Fox movie strongly broke continuity with the proper series.