Choosing the right pool cleaner for your pool will be based on the shape of your pool.
If a swimming pool is rounded and with rounded stairs and no square corners for a cleaner to get stuck in, a random style suction cleaner will be fine. Most random pool cleaners are identified by the circular rubber disk that they scuttle around on.
If your pool has square sharp corners then a random pool cleaner will likely get stuck. You can choose to go for a geared suction cleaner that will either constantly slowly turn or every few minutes reverse back a few steps before continuing. A good example of a geared pool cleaner is the Zodiac Baracuda MX8 or the Davey Leaf Wizard.
If you want a pool cleaner that will never get stuck and will scrub algae from the pool walls and surfaces, then robotic pool cleaners are the best choice. These include the Polaris 9300 and the Nitro (Admiral) Wall Scrubber