A good RPG isn't about the individual elements. It's about putting everything together in a complimentary way. In that respect, even the most cliche' story will be fun and enjoyable as long as each part works together in harmony.
I find it best not to ask others what makes a good game. Everyone has their own opinions and quite frankly, you sohld be more interested in your own ideas than those of others. The advantage of making your own game is you get to create something you, yourself, would enjoy. Look to your favorite games, movies, books and television shows for inspiration. There, you'll gain an idea for the the game's setting based on the types of things you enjoy watch.
Then, look to your friends, family, and even rivals/enemies for the basic character personality types. The abilties, weapons, etc will come as you flesh out the characters' prsonalities and histories.
Next, look to the world around you for both simple and exotic locales. Did you know Shigeru Miyamoto used a cave he explored near his hometown as a cihld to create the Super Mario games? Any everyday thing can become fantastic if you put your mind to it.
Look to your personal experiences for story ideas. Add in stories you heard from your friends or from older relatives. Then, sort through all of the information. Dress it up a bit (to save them the embarassment) and place it in a timeline for the characters. Add a splash of color from your favorite stories, etc and you have a storyline.
Now, take some things you enjoy doing and turn them into minigames. Did you work on a farm for a summer? Maybe, you remember helping your mom pull weeds from her flower garden, or you really enjoyed playing kickball in grade school. Any of these would make excellent minigames. The internet is there in case you need to look up any details.
Just remember: If you write about what you know, it's more believable. That's because you've lived it, seen it or just know how it's done. This gives you the knowledge to create it in detail.
You have a plethora of tools available to you for the purpose of creatign a game. find out what you enjoy most and create something you truly enjoy. If you enjoy it, others will, too.