I agree on Schiphol. I'm not the greatest fan of the KLM biz class seating, but still choose KLM over other airlines for the convenience factor. From the UK to International is the smoothest way to go, and I've made 20 min connections comfortably with all baggage. The other system I like there is that if you're inbound flight is delayed, you just rock upto the transfer machines in the lounge and print out a boarding pass for the next flight, everything sorted.
The other nice thing, when travelling hand baggage only on the cityhopper flights from the UK is the ability to drop your bag at the bottom of the steps and collect it on arrival. More airlines should offer this.
CDG is a nightmare....
HKG and SIN are very good.