My 23 month old son loves Wibbly Pig and Pajanimals. Both of those shows are on Sprout (you can record them or watch on demand). They're very short, which is good or bad depending on your needs

I think you can also watch them on www.sproutonline.com
He also loves Paw Patrol, which is a little faster-paced and flashy, so I tend to limit that one. I think that's on a nick channel.