I'll start with a few.

Aldgate East ----> Brick Lane - Brick Lane is now a major destination in London for lots of different reasons. It's one of the most famous streets in the city and it's evoloving ecology defines the area around the tube station. Plus there is already an Aldgate station just down the road, so it's not like the historical name is being lost.

Chalk Farm ----> Primrose Hill - Maybe a bit more of a controversial one this. My argument would be made around the same concept as re-naming Aldgate East, which is that in the 21st century the name Chalk Farm has really dropped out of usage for the area the station is in. I've hardly ever heard it used, while Primrose Hill is now a popular tourist destination and naming the tube station after it would hopefully result in it gaining more usage and taking some of the strain off of Camden Town. Especially at the weekends.

Battersea Power Station ----> Battersea. I still think the name choice was a mistake for this. What's wrong with just Battersea?