1 Mayday - tyre burst on a VC10 causing double engine failure, massive fuel leak (lost it all out of the port wing tank), ruptured pressure hull and loss of 1 hydraulic system. Oh yes, and it was dark and raining.
Safe landing at Brize Norton, no-one hurt and very impressed by the controller at London Control who let us route direct across all the airways - thanks mate, whoever you are.
1 Pan - smoke in the cabin during Atlantic crossing due to cabin conditioning compressor failure (VC10 again). Diverted into Shannon, lots of help from the folks there too.