Well I love that Season 6 is your favorite because it's one of mine as well & I feel like it's a more interesting pick than say Seasons 2, 3 or 5 as the best season. It's a love it or hate it season. I love how dark it got and how well it portrayed this "real life is hell" concept. Even though it's like the darkest season, there is still a healthy amount of humor throughout. It mostly loses points with me for how Amy & Dark Willow played out and for the nerd Trio being so awful. That's what ranks it below Seasons 3, 4 & 5 for me.
As for the comics, Season 8 is NOT mediocre. Most people complained that it had too big of a scope but I loved that. It portrayed Buffy and the scoobies how I always imagined them in my head- like underground rockstars/superheroes on an epic scale. I thought Season 8 was amazing throughout, even if at the very end, a very important character dies because I do know at this point that the character comes back! I don't want to spoil it for you but the character who kills this important character at the end of Season 8 spends all of Season 9 trying to resurrect them. I can't even over state enough how much weight Angel & Faith Season 9 carries- you seriously just have to read this book/season, even if you haven't read any of Angel After the Fall. Technically, you should just read all of After the Fall first, but I fell off with After the Fall towards the end and still got into A&F S9 easily. After the Fall was amazing to me as well though because it was awesome to see what Angel Season 6 would've looked like. It was cool to see how Wesley was still around in After the Fall, how Nina, Gwen & Kate were bigger characters, a lot of awesome new characters in the picture, Spike & Illyria's relationship & the character progression of Gunn- Again I don't want to spoil what happens to Gunn in After the Fall but you should read it.
I'm still reading Season 10 though! I'm so far behind, I haven't even gotten to Season 11 yet! I have to catch up for Season 12!