ARW, the two things you mentioned stand out for me as well.
Here's a collage of images that I think of when I think of each season of BB:
BB1: Red haired tatooed sweet Brittany; muscle man Josh; Chicken George dying his hair; Eddie competing with one leg.
BB2: Shana--using Hardy’s toothbrush to scrub the toilet bowl; Shana-putting potato chips on Autumn’s pillow; Krista--knife incident; Hardy working out and Nicole cooking and seeing their frustrated faces as they tried to best Will; Will’s giggly, mischievious face as he bested Nicole and Hardy; Boogey asking Krista to marry him @ the BB finale; Monica and 911; Bunky crying and shirtless
BB3: Marcellus not using the POV on himself!, Amy getting to come back to the show, quiet Lisa winning the show; Danielle and her “horns”
BB4: Jun, Erika, Allison scheming; this season doesn’t stand out as much except for them all having someone they knew in real life on the show and that theme not working well.
BB5: Drew screwing over Diane; Cowboy and his cluelesssness, Nakomis’s 5 finger plan, “4 horsemen”
BB6: April “Busto”, Howie/jackshack, Maggie holding court in the HOH room, Cappy and his temper, Kaysar making a bad deal in the challenge, Janelle being great in challenges and wearing gloves; shrieky Ivette; pouty James
BB7: All Stars-- Will and Boogey in the DR doing phone calls; George getting used by Will and Boogey; Will fake romancing Janelle; Janelle diving to get an item away from James in the challenge
BB8: Evil ##### banging the pots and pans, and his spitting, spitting, spitting; going off on several houseguests and being rewarded for being abusive; (and my interest in BB is in major decline at this point); Eric, America’s player
BB9: so awful I stopped watching after one and one half shows.
BB10: strategic Dan; Jerry going off on Memphis & Dan; April and Ollie acting as thought they were oblivious to the cameras, Memphis pretty much coasting to second place
BB11: Ronnie playing hard too early will be memorable; Jesse getting a pass to come back for a second season (yawn)
And some challenges that stand out:
Bbers shopping in luxury challenges
Laser and high wire challenges
Having to eat your fav dinner after its pulverized in a blender
Cheryl Crow playing for the houseguests in the backyard (what season was that?)
Decorating the gnomes
Houseguests getting to go out of the house for the Emmy’s or a helicopter ride, etc.
Houseguests trying to cram for challenges by memorizing details about the house and the game.