I never understand how stainless steel can be "worthy" of collection, it really a bet against the future demand market. A better "worthwhile" collection would need to comprise of more uncommon pieces or pricier option of the common models.
With SS models, you just won't know if it'll be the next big iconic model that the vintage market go crazy about, or will it just be another dud (yes it does happen, my dad bought a boy-size Rolex back in the days when it was hot in HK, there's basically no demand for it now).
Below is a list of my pick -
Daytona: Platinum with chocolate ceramic bezel - rare & expensive precious metal
GMT-Master: White Gold Blue-Red ceramic bezel "Pepsi" - precious metal with iconic bezel
Submariner: Two Tone Black dial/bezel or even the gold with blue dial/bezel - precious metal/rare dial color
Skydweller: Any option. The fluted bezel is functional (to set the 24-hour time). These are largely unknown models which I think will be sought after once it gets obsolete/new update due to a lack of attention for it now. Aren't we all human?

The picks are of my personal opinion. Looking forward to others' opinions on this!

Cheers
This message has been edited by utcpluseight on 2016-07-28 17:33:51