Motivate Your Employees - It's not only about the money

The picture attached says all I could think of :)

But there's never a possibility of keeping everyone happy anyways... More or less it boils down to the fact that the employee should know that the organization cares for the work that he's doing and the organization should also not be wasting any investments on someone who is not useful. Here's a list of observations which I think could bridge the gap between a Satisfied and a frustrated employee:

1. Don't hold back on the praise: Everyone quests for it and in my opinion it’s one of the easiest things to give. Plus any praise from the peers or the higher management (CEO, COO or the CTO) goes a lot farther than you might think. Praise every improvement that you see your team members make. Once you’re comfortable delivering praise one-on-one to an employee, try praising them in front of others.  
2. Make your ideas theirs but don't let the creativity die: People hate being told what to do. Instead of telling people what you want done; ask them in a way that will make them feel like they came up with the idea. “I’d like you to do it this way” turns into “Do you think it’s a good idea if we do it this way?”. There is a very thin line between a discussion about a decision and a forced decision, in my opinion one should never allow the employee's creativity to die out and make him just a machine to do only what you are telling him to. There should not be a case where the employee is totally let of the hook too, so that the goals stay intact.
3. Never criticize or correct. No one, and I mean no one, wants to hear that they did something wrong. If you’re looking for a de-motivator, this is it. Try an indirect approach to get people to improve, learn from their mistakes, and fix them. Ask, “Was that the best way to approach the problem? Why not? Have any ideas on what you could have done differently?” Then you’re having a conversation and talking through solutions, not pointing a finger.  
4. Make everyone a leader. Highlight your top performers’ strengths and let them know that because of their excellence, you want them to be the example for others. You’ll set the bar high and they’ll be motivated to live up to their reputation as a leader.  
5. Take an employee to lunch once a week. Surprise them. Don’t make an announcement that you’re establishing a new policy. Literally walk up to one of your employees, and invite them to lunch with you. It’s an easy way to remind them that you notice and appreciate their work.  
6. Give recognition and small rewards. These two things come in many forms: Give a shout out to someone in a company meeting for what she has accomplished. Run contests or internal games and keep track of the results on a whiteboard that everyone can see. Tangible awards that don’t break the bank can work too. Try things like dinner, trophies, spa services, and plaques.
7. Get rid of the managers. Projects without project managers? That doesn’t seem right! Try it. Removing the project lead or supervisor and empowering your staff to work together as a team rather then everyone reporting to one individual can do wonders. Think about it. What’s worse than letting your supervisor down? Letting your team down! Allowing people to work together as a team, on an equal level with their co-workers, will often produce better projects faster. People will come in early, stay late, and devote more of their energy to solving problems.
8. Throw company parties. Doing things as a group can go a long way. Have a company picnic. Organize birthday parties. Hold a happy hour. Don’t just wait until the holidays to do a company activity; organize events throughout the year to remind your staff that you’re all in it together. 
9. Share the rewards—and the pain. When your company does well, celebrate. This is the best time to let everyone know that you’re thankful for their hard work. Go out of your way to show how far you will go when people help your company succeed. If there are disappointments, share those too. If you expect high performance, your team deserves to know where the company stands. Be honest and transparent.

There's never gonna be a perfect world, yet I have one easy principle in life "An attempt may be a failure, but a failure to attempt is always gonna be a failure!" :)