I'm on my 9th class, one more to go. I found that Machine Learning had decent involvement from Isbell (he'd chat with us on Slack) and that Operating Systems and HPC and excellent professor participation -- they would hold weekly office hours (video conferenced) and were active on the forums.
There were 1 or 2 of my earlier classes that did feel phoned in, though (but did have strong TA involvement at least).