Series 3

Arguably the peak of Doctor Who. Casual viewers apperciated the strength of the stories and arcs and lusted after Martha. Discerning viewers identified with being the recipent of female attention but neither noticing nor acting upon it, and many first realized they were gay thanks to Tennant.

Meanwhile, /who/ and not a few samefags spent the best years of their lives researching the fascinating lore of Martha's Bong.

Why series 3 is the best season of Doctor Who
Main article: Why Series 3 is the best season of Doctor Who