1) For air travel Seat Guru gives you information regarding:
- Detailed seatmap graphics
- In-depth comments about seats with limited recline, reduced legroom, and misaligned windows
- Color-coding to help identify superior and substandard seats
- In-seat power port locations
- Galley, lavatory, exit row, and closet locations
and this includes which seats suffer from reduced foot room due to the placement of in-flight entertainment systems.
This site is a must read for me before I book any air tickets.
2) For London theatre tickets take a look at Theatre Monkey which does a similar job for London's theatres. It tells you which seats have restricted views & why and which seats are the best value.
This is not an advertisement for the above sites, I never take money or any other type of payment from the sites I occasionally recommend on this blog.