In another universe, Star Trek: The Next Generation would've looked much different. A concept that would have greatly affected the franchise's legacy had Gene Roddenberry gotten his way. There exists a sincere possibility that every other version of this cast would've failed to some degree whether it was failing to last seven seasons or failing to live up to the potential of the original version.
It's entirely possible that this group of actors and actresses created the best version of The Next Generation possible. Yet, it was a cast that was brought together in spite of what series creator Roddenberry wanted. While fans rightfully credit the man for the creation of the franchise, he often mishandled it. Unsure of how to properly expand on the original concept.
It's why these three names would've or could've been the names most associated with Star Trek: The Next Generation when Roddenberry had more control back in the 1980s.
Billy Campbell as William Riker
The Rocketeer himself, Billy Campbell was someone that Roddenberry wanted as his William Riker. Originally the character was seen as a younger, more intense version of James T. Kirk, and because of that, Roddenberry thought Campbell was the right man to play the part. Obviously, the part would go to Jonathan Frakes and Riker would be a more cool, less intense character than originally pictured. For fans of the franchise, you'd recognize Campbell most as Thadiun Okona. He appeared in one episode of the franchise, before reprising his role once again for Star Trek: Prodigy.
Patrick Bauchau as Jean-Luc Picard
In one of Roddenberry's least controversial takes, he wasn't a fan of an English actor playing a Frenchman. Let alone an English actor who couldn't really pull off a French accent. It's one of two major reasons that Patrick Stewart wasn't a Roddenberry pick: that, and his balding head. No, seriously, Stewart's lack of a head of hair made him someone Roddenberry didn't want on his show. So Belgian Patrick Bauchau was the man Roddenberry wanted. Thankfully he was talked out of it, as it's unlikely that anyone but Stewart could've made the character work to the degree it did.
Jenette Goldstein as Lieutenant Macha Hernandez (Tasha Yar)
Now, there's no concrete evidence this was a Roddenberry concept or pick, but thet original idea for the show had a security officer named Macha Hernandez, who would later morph into Tasha Yar. Obviously we know that Yar was played by Denise Crosby, but there was once a chance that Jenette Goldstein could've been the head of security on the Enterprise-D. Modeled after her character from Aliens, Macha was supposed to be like Private Vasquez. The character was very popular to the point that The Next Generation wanted their very own version. Complete with the same actress. The only problem, when the creators of The Next Generation found out that Goldstein wasn't actually Hispanic, they scrapped the idea completely. Goldstein, like Campbell, would later go on to appear in a Star Trek property as well. She appeared in a minor role in Star Trek Generations at the start of the film as a communication officer.