Arbiter's Grounds, Snowpeak Ruins, the goron Mines, The Lakebed Temple and the Temple of Time were all really enjoyable.
The Goron Mines was so innovative with their puzzles. The Lakebed Temple's design was also so interesting and complicated at the same time. I often got lost in that thing. Abriter's Grounds has such a good ambience to it and revived the Poe sisters in a way that went very well with this temple. The Snowpeak Ruins was completely unique has it was a ruined house. Plus, it included my favorite item, the Ball and Chain. The Temple of Time had such a great atmosphere to it and a great puzzle as well. The boss was largerly dissapointing, but I still liked it.
In the end, I voted for the Snowpeak Ruins, because of its unique puzzles, setting and item.