The TWD98 Youtube Channel has many series which include the following:

Key: Active= Still a running series, Inactive= No longer runnning

Command and Crash (Active)

Custom Tracks Showcase (Active)

Eyes on the Prize (Active)

Mario 3D World Co-op Let's Play (Inactive)

Fail and Recovery (Active)

Shortcut Challenges (Active)

Which Type are You? (Inactive)

Rate That Custom Track (Active)

Best Moments Weekly (Inactive)

MKWii Olympics (Inactive)

Mario Kart DS Missions (Inactive)

1 Vs 1's (Active)

Custom Tracks Online (Active)

Mario Kart 8 150cc Gps (Inactive)

Mario Kart 8 200cc (Inactive)