Here you go.
The ones marked out in red don't really add anything to the plot. The ones in yellow are still worth watching if you want to watch all but the most unnecessary episodes. I marked the episodes as I watched them, so I should probably go back through the list and make sure there isn't anything important to the overall plot in any of the ones I marked, but Clone Wars really isn't like Rebels where seemingly unimportant stuff turns out to be important later on. And remember, this list was created with the mindset of watching as much as possible and only skipping the most useless episodes.
But speaking of Rebels, I just finished rewatching season one of Rebels, and with watching them back to back, the difference in the overall writing quality is pretty obvious. Aside from the last few episodes of Clone Wars, while the story lines are great in Clone Wars, the writing in Rebels is leaps and bounds ahead of Clone Wars. It is a much better series overall from that perspective, especially if you exclude the last four episodes of Clone Wars, which is probably some of the best Star Wars content ever written if you've watched the rest of the series enough to be invested in Ahsoka's arc.