A policy of never selling a watch sounds like a good idea, because I always end up regretting my sales.
Rolex 16610, Tudor 79090, Tudor BB58, Omega Speedmaster, and IWC 3706 are my top 5, in that order. I only have a couple of CasiOaks at the moment, and can't shake the thought that I should pick up a Speedy or BB58 again some time soon. If I do I'm sure I'll sell them again after 6-12 months and regret it.
Not the worst regrets to have, to be fair. Better to have loved and lost than to never have loved at all and all that jazz.