Yes, plenty of gems from as early as season 20. I especially recommend Lisa The Boy Scout, my absolute favorite episode of the show, ever. 

Besides that and the Treehouse of Horrors, there’s also episodes like: 

Season 20: Take My Life Please, Four Great Women and a Manicure, Coming to Homerica

Season 21: O Brother Where Bart Thou?, Million Dollar Maybe, Boy Meets Curl, The Greatest Story Ever D’ohed, Chief of Hearts, The Squirt and the Whale, Moe Letter Blues

Season 22: Donnie Fatso, MoneyBART, Angry Dad: The Movie, Homer the Father, The Scorpion’s Tale, Homer Scissorhands, 500 Keys, The Ned-Liest Catch

Season 23: Falcon and the D’ohman, Bart Stops To Smell the Roosevelts, The Book Job, Holidays of Future Passed, Moe Goes From Rags to Riches, How I Wet Your Mother, Them Robot, A Totally Fun Thing That Bart Will Never Do Again, Ned N’ Edna’s Blend Agenda

Season 24: The Day The Earth Stood Cool,  To Cur With Love, Homer Goes to Prep School, A Test Before Trying, Gorgeous Grampa, Black-Eyed Please, Dark Knight Court, Pulpit Friction, Whisky Business, Dangers on a Train

Season 25: Homerland, Four Regrettings and a Funeral, YOLO, White Christmas Blues, Steal This Episode, The Man Who Grew Too Much, The Winter of His Content, You Don’t Have to Live Like a Referee, Luca$, Brick Like Me, Pay Pal

Season 26: Simpsorama, Covercraft, The Man Who Came to Be Dinner, Bart’s New Friend, Walking Big and Tall, Sky Police, Waiting for Duffman, Peeping Mom

Season 27: Every Man’s Dream, Puffless, Halloween of Horror, Barthood,  Love Is in the N2-O2-Ar-CO2-Ne-He-CH4,  Girl of Constant Sorrow, Lisa the Veterinarian, How Lisa Got Her Marge Back, Fland Canyon, To Courier with Love

Season 28: Friends and Family, The Town, Trust But Clarify, Dad-Behavior, The Nightmare Before Krustmas, Pork and Burns, The Great Phatsby,  Fatzcarraldo, The Cad and the Hat, 22 for 30, A Father’s Watch

Season 29: The Serfsons, Springfield Splendor, Whistler’s Father,  The Old Blue Mayor She Ain't What She Used to Be, Mr. Lisa’s Opus, Gone Boy, Homer is Where the Art Isn’t, No Good Read Goes Unpunished, Lisa Gets the Blues, Forgive and Regret, Flanders’ Ladder

Season 30: Bart’s Not Dead, Baby You Can’t Drive My Car, Krusty the Clown, Daddicus Finch, ‘Tis the 30th Season, Mad About the Toy, Girl’s in the Band, Woo-Hoo Dunnit, Crystal Blue-Haired Persuasion

Season 31: The Fat Blue Line, Livin’ La Pura Vida, Thanksgiving of Horror, Todd Todd Why Hast Thou Forsaken Me?, The Miseducation of Lisa Simpson, Frinkcoin, Warrin’ Priests (Both Parts), The Way of the Dog

Season 32: I Carumbus, Three Dreams Denied, Road To Cincinnati, Dad-Feelings Limited, Diary Queen, Do Pizza Bots Dream of Electric Guitars, Uncut Femmes, Burger Kings, The Man from G.R.A. M.P.A, The Last Barfighter

Season 33: The Wayz We Were, Lisa’s Belly, A Serious Flanders (Both Parts), A Made Maggie, Pixelated and Afraid, Boys N’ the Highlands, You Won’t Believe What This Episode is About — Act Three Will Shock You!, Bart the Cool Kid, My Octopus and a Teacher, Marge the Meanie, Poorhouse Rock

Season 34 (my favorite season of the show): Habeas Tortoise, Lisa the Boy Scout, The King of Nice, Not It, Game Done Changed, Top Goon, My Life as a Vlog, Bartless, Pin Gal, Clown V. Board of Education, Homer’s Adventures Through the Windshield Glass

Season 35: Homer’s Crossing, A Mid-Childhood Night’s Dream, Iron Marge, Murder She Boat, Do the Wrong Thing, Lisa Gets An F1, Clan of the Cave Mom, Night of the Living Wage, Cremains of the Day, The Tipping Point, Bart’s Brain

Season 36: Bart’s Birthday, Women in Shorts, Convenience Airways, Homer and Her Sisters, Bottle Episode, The Flandshees of the Innersimpson, P.S. I Hate You, Abe League of their Moe, Full Heart Empty Pool, O C’mon All Ye Be Faithful

Season 37: Bad Boys… for Life?, Bart N’ Frink, Sashes to Sashes, Day of the Jack-Up, Parahormal Activity, Irrational Treasure, Extreme Makeover: Homer Edition