One I have done three times and still enjoy is Telltale Heart (GCYY49) by Zoltarus (2/2.5) This was a very well done night cache in Orono. Anyone who has the opportunity really needs to do this. I have been out to it three times with different groups. Well worth the time. The hardest would have to be The Moat Mountain Progressive series. A long day of hiking but very satisfying. Clever is just a whole other thing. Laughing Terry's Right in Plain Site caches were good. Brdad's had some tough and clever hides, and I can't even remember some I'd done on trip out of state.