After a while of being subscribed to the same people and having the same adventures in your sporepedia all the time, what are you going to do? Here's what I do all the time:
1. Go to the online Sporepedia
2. Go to the "Browse" section
3. Set the filter to adventures, all adventures, newest
4. Look for any adventures with a good picture and description, and download them.
I've found plenty of awesome adventures this way. If you happen to stumble upon an unpopular creator with a sweet adventure, then sending them a nice comment will make their day and everybody wins. So try this out someday, maybe you'll find something cool.