I've done monoruns on most games
The original R/B were Kadabra/Zam if I remember correctly.
G/S/C was the usual Typhlosion.
R/S/E was Blaziken for R/S and Magneton for Emerald (I hated this last challenge). After managing these, I could solo with Rayquaza or Swampert over and over again.
FR/LG was first with Charizard, then Articuno, then Zapdos, and finally Mewtwo.
D/P/Pl was Garchomp, and then later on with Infernape.
B/W was the most time-consuming, trying to plan out. Eventually just used Hydreigon.
B2/W2 I haven't done yet, but I'm working on catching that Multiscale Dragonite right now. It will be my key to victory. Either that or my Lucario, who just steps on things waking up.
As a side note, all until Black and White were not EV trained, as I never cared about that until then.