Welcome aboard. Lots of good .45s out there. Most folks immediately think of the 1911 type, of which there are a great many good ones, there's also many good striker fired types as well as S&W's da/sa types, which I prefer. Try as many as you can get your hands on and decide which type works best for you.
My two .45 acp's are the Springfield Armory GI model, and S&W 457 which is my primary carry gun.