My own journey has taken me through a great many historical periods, form factors, layouts, switch types, plate/case/pcb mount, keycap materials/profiles/printing methods. Switches have included various terminal linears, foam & foil, Hi-Tek Space Invaders, various Alps/Matias, just about every Cherry mx and clones, beam spring, Model F buckling spring, Model M buckling spring, and Topre 45 and 55g.
Conclusions about favorites:
Form factor: 60% and TKL, but nothing larger than TKL and nothing in-between 60% and TKL.
Layout: HHKB.
Switch: Lubed + Silenced Topre 55g > Lubed + Silenced Topre 45g > IBM Model F Buckling Spring > Blue Alps > Brown Alps > Matias Click> Matias Quiet > Gateron Yellow.