...it is a 'Sophie's Choice' decision about the watches in the current collection then, as with Art I suppose, the defining factor would be sentiment rather than value, rarity, function or all round suitability. The problem then, however, is that several watches still qualify in that category : father's watch, gifts from wife etc etc.
In the final analysis, for me it would be the watch that my father gave me on my thirteenth birthday a lifetime ago: an old Tissot Seastar chrono.
Cheers,
pplater.