I only had blue on my gameboy and later crystal when I got the gameboyplayer on my gamecube, of which I think crystal is the better one. I dont know if those are possible on 3ds? Also have the 3 ranger games on virtual console, but I think its better to start with the main games.

X and Y are really good imo

as far as 3ds games go, omega ruby and alpha sapphire are great to start with, or u could play emerald or platinum if u wanna experience some older ones (gba/ds)

i personally think start with Omega Ruby / Alpha Sapphire first and then visit older games afterward.