For me on Saturn as a kid was Tomb Raider, Croc, Virtua Cop, House of the Dead, Sega Rally and Virtua Fighter.
Mega Drive was Phantasy Star, Sonic, Altered Beast, Super Thunder Blade, Vectorman, Ecco, Decap Attack and god knows what else.
Still trying to find a decent condition copy of Lost Vikings for it.
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The problem with the whole 3rd party dev thing was this.
Sega and Nintendo just let 3rd party devs do what they want during the Saturn, SNES, N64 and Dreamcast era.
Sony however provided full on support and even sent some of their own devs out to help them.