I don't really like geraniums either.

I'm going to assume you're in full sun (6+ hours per day)

By longevity, do you mean life of the plant or length of bloom?
Life of plant, then you're talking perennials. And it'll be a bigger challenge to get a perennial to survive in a pot that you keep above ground.
But, a perennial is probably a better idea to get you height.
You've probably seen most everyone using Draecena Spikes... everyone is doing that! But it's less common to see someone using an ornamental grass for it.
You could also do a Coleus in the Kong series. They're soooo awesome. Shorter coleus can also have awesome foliage color. And sometimes foliage color is more dramatic than blooms.

For blooms all summer, try Wave Petunias or Million Bells.

If you have shade, check out impatiens.

By the way, one of the best sites for container garden recipes is ProvenWinners.com. See link below:

Here is a link that might be useful: Proven Winners Container Recipes

I like Melissa's suggestion of using coleus. I do this frequently especially the sun coleus. You can find some that easily reach 2 or more feet in height. If your entry is partially shaded you might want to try some elephant ears for height. Some types are said to be able to take full sun, but I have my doubts about western exposure unless you have some shade. Her suggestion of checking out the proven winners website is also excellent.