The Cessna 208 Caravan is a single engine turboprop with a fixed gear and a non-pressurised fuselage. It has large rectangular cabin windows. This type is often confused with the Quest Kodiak, which is very similar in appearance. The easiest way to keep them apart is by the nose. The standard Caravan has air intakes on both sides of the prop spinner, and a large exhaust on the right side of the fuselage.
The Cessna 340 (and 335, the non-pressurised version) can be easily mixed-up with aircraft of the Cessna 400 series. The general appearance is the same, the differences are in the details. Good to known is that the Cessna 335/340 always has four cabin windows and tip tanks, and a thinner fuselage than the larger 400 series.
Cessna 400 series (oval windows)
Differentiating between most of the Cessna 400 series twins with oval cabin windows is quite hard, as most look very similar, as is the Cessna 340. However, when looking at details the main models can be recognised. The shape of the cockpit and cabin windows is the best way to recognise them from the Beechcraft 65 and Piper PA-31.
Cessna 400 series (rectangular windows)
These Cessna 400 series twins have rectangular instead of oval cabin windows, but for the rest they look very similar. Fortunately there are fewer subtypes. The shape of the cockpit and cabin windows is the best way to recognise them from the Beechcraft 65 and Piper PA-31.
Cessna 408 SkyCourier
The Cessna SkyCourier has a nearly square fuselage, that quickly tapers behind the large cargo door on the left side aft of the strut braced wings. On top is a quite tall vertical stabiliser with T-tail. Finally the aircraft has a fixed tricyle landing gear. All in all not difficuly to recognise. (photo Textron Aviation Inc.)
The Cessna 441 looks like the Caravan II, but has smaller, more rounded cabin windows, which are still significantly different from the oval or rectangular ones on the other Cessna 400 series aircraft. Compared to the Caravan II the horizontal stabiliser is attached to the fuselage, instead of the vertical tailplane.
The Citation Mustang looks like a small CitationJet, but there are more differences: the Mustang has ventral fins, wide, oval cabin windows and different cockpit side windows, like that of the Premier I.
The Citation CJ4 is the only CJ family member with a (slightly) swept wing. All others have a straight wing.
The Citation Excel series is essentially a crossbreed of the Model 750 Citation X and the Model 560 Citation Encore. The former supplied the fuselage, which was shortened. The wings and tail are of the Citation Encore.
The Citation III was the first Citation with a swept wing and a T-tail. It can be distinguished from similar bizjets by its cockpit windows, squared off oval cabin windows, large thrust reverser fairings and bullet fairing on top of the vertical stabiliser.