Name 3 classic mini-monitors worth keeping- Why?

I'll second the Proac Tablette 50 sig's. Love mine!

I heard the ProAc Super Tablette's years ago and fell in love, so no doubt the later Tablette 50 sig's are awesome too!

Rogers LS3/5a's

Celestion  SL6

No one does it like the Brits when it comes to 2 way bookshelf speakers.  ProAc, Epos, Spendor, KEF, Mordaunt Short, Castle, Monitor Audio, Wharfedale, Mission, B&W all have a place at the table, IMHO. 

MAGICO Mini 2s because they sound wonderful.

Spendor SA1 from 2009.  Fantastic tonal speaker, sealed-box (acoustic suspension) so usable in applications where the much more widely used base reflex ported speaker would be problematic (e.g., close to walls or in cabinet, among others).

Technics SB C700 monitor, Diapason Adamantes, Omega RS8, Tekton IM, Norh 9.0 marble Speakers...I own all of them, I still have them, Alnico Omega as well...