1. Ty Glas and Birchgrove are ridiculously close. When I was station bashing on the Coryton Line, these were the last 2 I needed, so I got off at Birchgrove and walked back to Ty Glas. The walk only took around 2 minutes, would have been shorter if the road was right by the track! Still, a station in the middle would save time I'd say!
2. Anerley and Penge West are close, again scratching off Anerley, I could see Penge West from the former station, handy to see when your Croydon bound train is due!
3. Covent Garden and Leicester Square, we know that one and most expensive for a single or return too!
4. Castle Bar Park and Drayton Green are close enough, walked it before and didn't take that long.
That's some I can think off at the top of my head