My favorite TV show from my childhood would definitely be Drake & Josh. This show was on Nickelodeon like 12-15 years ago, and it was a classic. When I was around ten years old, everyone that I knew was watching it.
It has to be either Scooby Doo or Spongebob Squarepants. In terms of Scooby Doo, I have to say that I loved the episodes that were shown when I was younger as the newer ones aren't as great and just seem a bit weird. Spongebob is obviously another great especially considering people of all ages can love that show