Amsterdam is one of the easiest for transfers from the UK to International as you remain in the same terminal, and pretty much always use the same gate. Flying Business however, the lounge is crap.
LHR Terminal 5 is just a pain, it's more like a shopping centre, it's a lot of hassle and they never announce flight gates until very late on.
Charles De Gaulle, is another crap airport, especially if you have to transfer terminals coming from the UK, as you literally end up outside the entire security area and have to go back in, and the terminal is so bare and overpriced.
Hong Kong, great place to transfer, one terminal, easy to get around,
Singapore, great place to transfer (if flying into Changi main terminal, if you goto the budget terminal then AGGGHHH).
Dubai, is fairly good and flying emirates is always a pleasure, but you seem to spend half an hour on the bus going to the terminal after landing.
Cairo, aghhhhhhhhhhhhhhhhhhhhh (business class lounge, erm whats that???)
Helsinki, not so bad, not so great. Busses to the terminal again
Doha, OK, not great, busses to the terminal though
Then the US hubs are ok, but if your transferring to/from international flights they often don't have transfer facilities and you have to actually enter the country go outside and go back through security !!!!!
Miami, aghhhhhh, english food please????
Houston, very good
Vancouver, ok
JFK, ok
erm, can't remember the rest,
