27x13 The Parting of the Ways [season finale; 4th watch]
Here is where all the good bits are: the Dalek Emperor ("they survived through me!"), the Dalek army flying through space (thousands of them!), Lynda's death (poor Lynda!), David Tennant's first few moments (crikey he looks young!), and so on and so on.
Plus, the emotional wringer Rose goes through, brilliantly played by Billie Piper, now brings with it a realisation of how emotionless the Moffat-era companions have been, and how little the actors have been stretched by those roles. Shame.
4x20 The One with All the Wedding Dresses [4th or so watch]
6x02 Black-Winged Redbird
[Watch it (again) on Demand 5.]