Pick whatever one suits your fancy. Just remember that the largest plug-in heater will be 1500 watts, which is about 12.5 amps or just over 80% of a 15 amp outlet.
1500 watts = 5100 BTU's. So any 1500 watt heater you buy will put out 5100 BTUs, whether you paid $20 at Walmart or $150 bucks somewhere else.
Some have additional features such as different heat levels (750/1500 watts, 500/1000/1500 watts, etc.), built-in thermostats, oscillating discharge, different fan speeds, etc., etc.
Most simply use an electric coil that gets hot and a fan blows air through it. Some use ceramics, which don't usually have a red-hot element. Some actually heat oil, which provides a heat mass which will continue to add heat to the room as it cools down. There are others.
But remember, 1500 watts = 5100 BTU's. So don't overpay for a heater.
Definitely don't buy the Amish heater!