Heck yes!
Project Tupolev Tu-154B-2
http://www.protu-154.net/forum/viewtopic.php?t=12512
This aircraft is one of the most complex addons available for FSX, and is a "systems simulation" of this three-engined airliner.
I have an entire unofficial "flight school" for it just due to the complexity involved:
http://aviationcafe.co.uk/Index/viewforum.php?f=59
Ivan Jurcaga's MiG-21MF
http://migsim.ic.cz/emefka.html
Less complex but still requires some reading. Very enjoyable and fast fighter jet!
Tim Conrad's An-32
(available on most websites)
Cargo/Passenger twin turboprop with nice VC. English language and not as complex as the others.
Kirill Konovalov's Il-86
http://avsimrus.com/f/fsx-aircrafts-79/ilyushin-il-86-fsx-34990.html
Not fully decked out systems-wise, but it looks great!
The above are all freeware.
The following is payware:
Virtavia
Ka-50 "Black Shark" attack helicopter.
(available at most flightsim stores)
Very nice VC but not complex systems-wise. Still looks good and is enjoyable.
Virtavia
Mi-28 "Havoc" attack helicopter.
(available at most flightsim stores)
I don't have this one and it's getting pretty old, but it seems like it would be nice.
The above is all FSX-Native too. There are a number of FS9-era ports that work to varying degrees as well.
There's more but I need to look at what I have. I'll be back.