A good title is paramount to grabbing people's attention and, most importantly, making them remember it. You don't want something too long. (It should fit nicely on the marquee or be easy to read on a standard TV screen or on the spine of a book). You do not want something too generic or too bland. As an example of personal taste, I despise titles with numbers in it, or anything that's too similar to another title.
A great ending is key to an audience's lasting impression of your story. It needs to be satisfying. (Whether it's happy or sad, whether it answers all the questions raised by what preceded it or leaves you hanging for more, all can satisfy viewers if handled properly). Know when to end your story, don't drag it out. And don't pull a Sopranos by ending it too abruptly without some sort of proper resolution, even if it is only a cliffhanger.
Even though there are many other vital elements to creating an entertaining story, I strongly believe that with a good title and a great ending, half your work is done. The title is the first thing people experience and the ending obviously is the last thing they see. Having a catchy, unique, easy-to-digest name for your project and knowing where your story will end are big components to making your tale enjoyable.
Then, of course, you have to create all the terrific content in-between! A brilliant title and a fantastic ending can't save a horrible story (and I suppose great tales can have wretched titles and lackluster endings), but having a good title and a cool ending in sight is a great start.