Some great standbys are Hershey's Perfectly Chocolate Cake and there are some long threads on yellow and white cakes. I don't save those threads, but someone will come along and give you links.
Many of us modify the chocolate one, so be sure to read down through the threads.
Another way to get some great recipes is to start a thread with asking for just one flavor. You will get the favorites. Then go on to another flavor with another thread.
So happy to see a convert. Don't give up if you fail a few times. We all do.