I assume you mean the best championship battle in the 20 years you've been following GP, as there have been (IMHO) better seasons: the battle between Prost and Senna in 1988, when they were both driving for McLaren: they won all bar one GP between them. And that's not including great battles like that between Hunt and Lauda in '76.
This season has been exciting, for sure, but the quality of driving by Max (although he's not alone) leaves a lot to be desired.
It'd be arrogant of me to say I know better, as I wasn't around to watch those seasons. Certainly, from archive footage I've seen (plus the help of films/documentaries "Rush" and "Senna", they looked like fantastic seasons with very exciting championship battles.
I also agree that Max crossed the line in SA, and should have been penalised more heavily for it.
But in terms of on-track battles/incidents between the two, this season has been like a movie script. Yes, SA got a bit silly, but it was still a fierce battle, and given seasons gone by where the two championship rivals would barely have a battle on track, this season we've been utterly spoilt. Bahrain, Silverstone, Monza, Brazil, and SA all saw them in a dramatic on-track battle/incident - then you can throw in Imola, Portugal, Spain and France as well when they were side by side for the lead at some point.
Unless the archive footage has been lost over time, I can't see that Hunt/Lauda or Prost/Senna in as many on-track battles as this? Certainly when I think back to say 1998-2000, whilst the Schumacher/Hakkinen rivalry was fierce, the only times I recall them being side by side or in a fierce battle are Italy '98, Hungary '00, Spa '00 and Japan '00. I may have missed some in there, but the point still stands I think.
And Lewis and Max are tied on points! Forgive my childishness, but I'm like a kid at Christmas - I can't WAIT for Sunday. May the best man win.