My general likes and dislikes are pretty simple - I prefer exhibits in the round to ones with doors I have to find. Simple really is better - when I'm impatient I will give complicated builds I have to walk around inside a miss unless something about the outside intrigues me, and text is incredibly difficult to read in three dimensions. On a related note - smaller isn't necessarily a bad thing; having run across a few exhibits that looked like boxes until I scrolled back A lot of displays try to cover everything, but I think it's really best to pick a straightforward idea and execute it clearly, identifying yourself if that's important. Keep in mind the sheer amount of creations people are putting out, and the time involved in trying to see everything, and be respectful. My absolute favorite are ones which are viewable from above, of for which I can find an angle which excludes its surroundings. One sided invisible layers work beautifully here - allowing one to see in but also allowing for angles from which one can photograph everything. I'll admit this is a personal peccadillo - I really like to photograph things in either isolation or in pleasant layering, and the latter is nearly impossible on the birthday sims.
There are signs along the way for the "SLB HUNT", an event where people leave free items around for you to find. The type and quality is highly variable - this is not a place to get shiny clothes and accessories, but rather a place for enthusiasm, love, and oddity. In contrast to the often slick commercial side of Second Life, this is the place for the enthusiast and harkens back to Second Life's more by-the-pants salad days. There's a lot to experience and enjoy, and a few quiet gems which I wish I could keep long after the birthday sims have faded into the ether again.
Must visit spots:
Wind-Song Garden, on Spectacular. It's a calm garden with flowers which play sounds when you touch one. There is a master flower to turn them all on. Created by Rey Weyland.
Once Upon a Family, on Stupendous. One of the better uses of text that I saw, and a very clear and cohesive design that articulated the theme beautifully.
Childhood Dream Dome, on Stunning. Accept the pop-up menu and follow through one boy's story of his Second Life.
A few interesting stops:
Impressive Gift Stash
Spectacular Gift Stash
Electrify Gift Stash
Places to go for Pod Tours of the sims:
Wonderous Pod Station
Electrify Central Pod Station
( More pictures here. )