Heheh, nice one, Shimrod. I'm still with my first edition of Stace and will just have to risk being out of date with my Latin names. I still dip into my CTW Excursion Flora occasionally for old time's sake. I also have the New Atlas of the British Flora with which I can continually disappoint myself when I think I've found something new (someone else always got there first!), but my current favourite for a quick looking-up is Wild Flowers of Britain and Ireland by Marjorie Blamey and the two Fitters.

Floras aside, The Beethoven Quartets by Joseph Kerman is my most thumbed book.