Small tidbit we don't see talked about often: Tekken Tag Tournament's iconic opening scene actually has a small cameo appearance by Ridge Racer R4's Reiko Nagase, very fittingly via a billboard during the brief high speed chase that introduces Lei Wulong. It's only on screen for a handful of frames and extremely easy to miss.
This going so unnoticed in such an iconic cutscene is pretty crazy. Two of Namco's most fondly-remembered games of all time collide with this super low key crossover.
Really like the Limp Bizkit and Shadow Wizard Money Gang looking guys, Flash and Grim, in the Crazy Frog Racers.
They switched their character select animations between games.