I don't buy many mods but these two stood out to me and I picked up both.
Not cheap but VERY high quality and fixes a sore spot with the game:
https://pinside.com/pinball/forum/topic/woz-witch-red-smoke-mod
Very cheap and awesome mod:
https://pinside.com/pinball/forum/topic/metallica-pro-skulls-in-coffin-mod