To compare pumps you need to know the brake HP, which is the listed HP times the service factor (SF). Pump manufacturers sometimes use words like full rated, max rated, up rated, etc to hint at what the SF is. A 3/4 HP full rated pump is often the exact same pump as a 1 HP up rated pump in the same line except with a different name plate.
If you are going with a single speed pump, the 3/4 HP full rated WhisperFlo pump has a SF of 1.67, so 1.25 brake HP. The energy efficient version, model WFE-3, is a great pump, uses less electricity to move the same amount of water than many other similar pumps, and is fine for most any non-huge pool without a spa or water features.
For two speed pumps, the 1 HP full rated dual speed WhisperFlo, WFDS-4, is often a good choice (again assuming non-huge, no water features). It's SF is 1.65 so 1.65 brake HP. The 3/4 HP dual speed is 115 volts only, which is often a problem. Sadly the dual speed pumps are not currently available in an energy efficient version. Even so, the 1 HP dual speed on low speed will use less electricity to move the same amount of water as the efficient version of the 3/4 HP pump.
The next step up would be something like the IntelliFlo variable speed pump. For a simple pool with no water features it may seem like overkill, but the energy savings can be dramatic. This is a really good choice for people in areas with particularly high electric rates.