5. The Doctor and Wilf
I think if you happen to run into a wide-eyed older man who sells newspapers on the corner and seems to perennially wear a winter cap with antlers budding from it, you might think he's a little off. And when he begins ranting about his times star-gazing and alien lifeforms on earth, you might be convinced of it. But Wilf, Donna Noble's grandfather, manages to avoid all the normal traps seen with conspiracy theorist whackos. He's sweet and (like his daughter's married name) noble, and after Donna's memory is erased Wilf is perhaps the one person who understands the Doctor the best. In the End of Time Part II, The Tenth Doctor and Wilfred find themselves in traps set by both The Master and the Time Lord President played by Dalton, Timothy Dalton. Wilfred, locked in an isolation chamber awaiting a lethal dose of radiation, can only be saved by the sacrifice of another. The Doctor and Wilfred have a Mexican stand-off of self-sacrifice, each believing their life worth to be inferior to their companion. The Doctor ultimately receives the fatal blast of radiation, stating this sacrifice would be his honor. Wilf shouldn't have felt so bad since humans die and Doctors just regenerate. Anything else by Number Ten would've just been plain rude. Wilfred's encounter with the Doctor leads right into #4...