>>52291001Platinum is super good imo. I like HGSS but I don't know if I'd recommend it for an entry point.
Honestly, if you like the graphics start with Pokemon Red, or maybe Shin PokeRed. If not, Fire Red/Leaf Green. FRLG are remakes of the first game, and they shouldn't take too long. Playing on an emulator means speed up, which means grinding is virtually a non-factor. FRLG also play at 60FPS. Ultimately, I think Gen 3 (FRLG/RSE) is the ideal starting point for people interested in experiencing Pokemon that don't know anything about it.
Emerald is an enhanced version of Ruby/Sapphire, and should provide the best single-player experience of that setting, but if you're interested in seeing what changes between versions, start with Ruby or Sapphire, then play Emerald. If you don't care about that stuff just go in with Emerald. It doesn't matter if you play Emerald or FRLG first because they take place at the same time, but like I said, FRLG are remakes of the very first installments, so you'll get a better idea of how Pokemon started and what it turned into over time with those.
If you can stand to play Red (or Shin Poke Red) then move onto GSC.
HGSS are remakes of GSC, which take place 3 years after Red/Green (or FRLG) and at roughly the same time as Diamond/Pearl/Platinum. Technically, HGSS seems to be happening just a tad bit earlier, but on the whole those games feel like they should be experienced last. It helps that HGSS specifically was released after Platinum, and seems to have been built inside of its engine.
As for recommending Platinum over Diamond/Pearl; the disparities between Diamond/Pearl/Platinum are not nearly as pronounced as Ruby and Sapphire, and then Emerald, so it doesn't matter. Also, it's not as easy to blitz through Diamond, Pearl, or Platinum, so consecutive Sinnoh playthroughs are a lot more daunting than Hoenn playthroughs. Pretty sure D/P/Plat are locked at 30FPS outside of battle.