For everyone's benefit, here is a list of the cards that most obviously synergies with Lucid Dreaming (as of Dream Eaters). Please mention any that I miss out in the comments:
Signature Cards:
Stack-able Hand Assets:
- Magnifying Glass (and its upgrade)
- Book of Shadows (and its alternative)
- Ritual Candles
- Spirit Athame
- Survival Knife??? (Can you trigger two copies of Survival Knife on the same attack?)
- Sign Magick
- Hawk-Eye Folding Camera
Disposable/Temporary Assets With Persistent Effects:
- Beat Cop (and its upgrade)
- Police Badge
- Baseball Bat
- Knife
- Brother Xavier
- The Red-Gloved Man
- Gravedigger's Shovel (and its upgrade)
- Lantern (and its upgrade)
- Key of Ys (when not playing with the Taboo List)
- Tennessee Sour Mash (and its upgrades, both of them)
Most of the Myriad Cards:
Cards That Synergies With Themselves:
- Hot Streak (2) (not so for Hot Streak (4))
- Contraband (and its upgrade)
- Expose Weakness (1) (not so for Expose Weakness (3))
- Vantage Point
- Fence
And that should about be it. Of course Lucid Dreaming has additional functionality outside of these cards; drawing the second copy of your 5xp sink or your assets with limited uses is always a good thing. And of course, not all of the cards presented are particularly powerful with Lucid Dreaming (e.g. Knife); this list it just a time saver for everyone who wants to know where Lucid Dreaming goes above and beyond a card draw.