RedisVon Eric Antoine Scuccimarra
I've been messing around with Redis for a little while now and I'm using it in a couple places on this site. The first thing I did was I started caching some DB queries that get performed a lot, like the main blog page, the blog archives menu and the list of recent posts on the home page. Laravel's Cache facade makes caching really easy, and you can switch between the default cache driver which caches to files and Redis without changing any of the code. For some pages I use the Laravel Cache facade, for others I use the Redis facade to cache directly to Redis just for some variety. In general it is probably much better to use the Cache facade than the Redis facade because if you want to switch to a different caching mechanism with one change to the .env file instead of having to rewrite all of the code.
I also use Redis to queue some tasks which don't need to be done synchronously, but that's another post.
I never used Memcache because I didn't like the fact that it's all stored in memory, so if the server goes down you would lose all of the data in it, but Redis persists data to disk by default so it provides the speed of keeping data in memory with a very low risk of losing the data. In my case, I store the data in the DB and cache it in Redis, but if I were to start from scratch (and had plenty of RAM on my server) I would probably keep a lot more data in Redis.
So, to summarize, I think Redis is awesome and I will definitely make more use of it in my stack in the future.