Watching those OPs reminded me that there was a stretch from about 1998 to 2007 that was just an absolutely incredible time for anime:
1998 - Outlaw Star, Silent Mobius, Cowboy Bebop, Trigun, Lost Universe, Serial Experiments Lain, His and Her Circumstances, Bubblegum Crisis 2040, Initial D, Princess Nine
1999 - Crest of the Stars, Turn A Gundam, Betterman, GTO, Legend of Black Heaven, Excel Saga, The Big O, Dai-Guard, Reign: The Conquerer, One Peice, Hunter x Hunter, Now and Then Here and There, Blue Gender
2000 - Boogiepop Phantom, Banner of the Stars, Niea_7, Vandread, Sakura Wars, Miami Guns, Carried by the Wind: Tsukikage Ran, Inuyasha
2001 - Earth Maiden Arjuna, Noir, The Soultaker, Super Gals!, Fruits Basket, s.CRY.ed, Hellsing, Kaze no Yojimbo, Angelic Layer, Haré+Guu
2002 - Full Metal Panic!, RahXephon, Azumanga Daioh, .hack//Sign, Magical Shopping Arcade Abenobashi, Witch Hunter Robin, Saikano, Ghost in the Shell: Stand Alone Complex, Haibane Renmei, Gundam Seed, HeatGuy J
2003 - Wolf's Rain, Gunparade March, Kino's Journey, Last Exile, Texhnolyze, Scrapped Princess, Full Metal Panic? Fumoffu, Narutaru, Full Metal Alchemist, Planetes, Cromartie High School, R.O.D. TV
2004 - Paranoia Agent, Ghost in the Shell: SAC 2nd Gig, Samurai Champloo, Monster, Gantz, Sgt. Frog, Samurai 7, Genshiken, Gankutsuou: The Count of Monte Cristo
2005 - Peach Girl, Eureka Seven, Speed Grapher, Victorian Romance Emma, Kamichu!, Mushishi, Aria the Animation, Noein, Paradise Kiss, Mahjong Legend Akagi, Honey and Clover
2006 - Ergo Proxy, Ouran High School Host Club, Black Lagoon, Gintama, Nana, The Third: The Girl with the Blue Eye, Le Chevalier D'Eon, Kemonozume, Welcome the NHK, Code Geass, Death Note, Ghost Hunt, Yamato Nadeshiko
2007 - Gurren Lagann, Darker than Black, Claymore, Seirei no Moribito, Bokurano, Dennou Coil, Baccano!, Mononoke, Ghost Hound, Kaiji, Moyashimon
spoiler (click to show/hide)
2008-2017 - nothing