There are over 10,000 trillion alien races/civilizations (100,000+ per galaxy; excluding humans) in the Titan AE Universe.
There are trillions of alien races (excluding humans) in the WildStorm Universe.
There are over 10,000 trillion alien races/civilizations (100,000+ per galaxy; excluding humans) in the Outlaw Star Universe.
There are over 10,000 trillion alien races/civilizations (100,000+ per galaxy; excluding humans) in the Code Lyoko Universe.
There are over 10,000 trillion alien races (100,000+ per galaxy; excluding humans) in the Deadman Wonderland Universe.
There are over 10,000 trillion alien races/civilizations (with 100,000+ per galaxy; excluding humans) in the Animorphs universe.
There are no alien races in Cowboy Bebop (But in the Cowboy Bebop universe, and fan-fiction also; there are trillions of them (with hundreds of thousands of them in each galaxy)).
There are trillions of alien races (with hundreds of thousands of them per galaxy; excluding humans) in the Big O anime universe (in reality; Paradigm City is a computer simulation).
There are over 10,000 trillion alien races/civilizations (100,000+ per galaxy; excluding humans) in the Damocles Universe (the universe Sigma, the qeelocke, Damocles, the Sword, and One-Eyed Jack's crew originated in).
There are no known alien civilizations in our universe.
No, they are not. There are many similarities in Law, the races, some of the background, but they are not considered to be in the same game universe.
If you counted 1 intelligent alien civilization per second, it would take 400 million years to count all 12,600 trillion intelligent alien civilizations in the universe.
at least 12,600 trillion or more. For now, it is unknown.