Like Mr Souter, I have always thought private number plates to be naff, especially the ones where it is supposed to spell out a name, but doesn't (unless you are drunk and standing some distance away).
A long time ago, I used to work for a Saab dealer, the boss was obsessed with private number plates, all the demo's, and the parts van, had plates with some reference to Saab. Unfortunately, due to the combinations of numbers and letters available back then, most just had 'sab'!.
However, a demo's, run by one of the salesmen, had what was in my opinion, the best combination of number plate to car. The car in question was a classic shape Saab 900 turbo 16S, the plate on it was FLY 900T!