Instead of having Anna, Luke, Zack and Lindsay be filler they could have been integrated into the main cast with their own subplots as well. It would have been cool to see Anna and Luke date in an opposites attract type of situation. Maybe she gets into him when she sees that he's changed from when he was with Marissa and he's no longer the typical douchey jock. I could also have seen Anna and Lindsay becoming best friends and Lindsay being friends then enemies with Taylor. I could have seen Lindsay and Zack eventually dating as well. It would have been fun to see Taylor as a villain for school storylines involving Lindsay and Marissa during seasons 2-3 before getting a redemption towards the end of season 3. I liked Ryan's friendship with Luke and I think that Seth and Zach should have developed a solid friendship once Zach got over Summer and started seeing Lindsay. It would have been more dynamic to have more teens in the main cast. There could still be the core four main teens but I would've liked to see more of a longterm support teen cast like other shows such as Buffy had. Buffy had the main three (Xander, Buffy, Willow) but they also had long-term supporting teens (Cordy, Tara, Oz, Anya). Beverly Hills 90210 also had a large teen cast during the high school/college years but the central storylines mostly revolved around Dylan, Brenda, Kelly and Brandon during the high school years with Donna and David becoming more prominent during college years. Anyway I think it would have been really fun and interesting to have this be the main teen cast for seasons 2-3. The core four needed more friends besides their little group.

What if instead of a core four there had been a core six with Luke and Anna in main cast durin season 1 and then 2 onwards it became a core 9 with Lindsay, Zack and Taylor being added to the main cast as well. I wonder what it would have been like if The OC had a Beverly Hills, 90210 level teen cast