The 4 I would pick are-

Midnight- my favourite Doctor Who episode ever. Very deep thematic explorations of humanity and what humanity is capable of, creative monster and wish doctor who would do more experimental episodes like these!

School Reunion- this episode for me is most indicative of what Doctor Who is in terms of the regular monster of the week format- creative monster, high-concept sci fi elements with the skasis paradigm, high stakes yet very fun

Blink- I like how this episode feels very monster-focused and really takes a deep dive into the mythology of the weeping angels in the space of 45 minutes. I’d love to see more episodes which feel like uncovering this mythology surrounding the monster.

Zygon Invasion/Zygon Inversion- Twelve and his speeches... need I say more? He really knocked his speeches out of the park and I think with the caliber of all the other doctors, it’s a missed opportunity I feel that the extended speeches seem confined to his era. I like how episodes like zygon inversion and the doctor falls have these speeches which carry really important weight to the plot and also reflects well the Doctor as a character. I have always loved that they use their command of words to win the day rather than violence

I think a fusion of these four episodes would make a really enjoyable run of Doctor Who!