Personally, I dislike Let's Play videos, especially because a lot involve someone being loud and annoying trying to crack 'jokes'. However, I do like developer commentaries as they provide very insights into a games creation, and may talk about cut features and what could have been. With the increasing popularity of Let's Play videos, we actually have gotten some interesting developer Let's Plays over the last couple years. These are a few of the developer and creator commentaries that I like.
Conker's Bad Fur Day
Day of the Tentacle
These are a few of the commentaries that I like. If you have some that you like please let me know!