Yak-3 and Cessna 172

F8F and MiG-29 visually
F4U-4 and F-20/F-5E are my true favorites

F-15 and Su-27

I have 6 that I can't decide which one I like the most:

(Cold war)
F-105 Thunderchief
MiG-31
J-35 Draken

(WW2)
Supermarine Spitfire
P-51 Mustang
Gloster Meteor

Maybe Mirage III

Su-35S

Antonov AN-2

F-35,J-20,BF-109,P-51

All Boeing jetliners (707-777 except 787)
P-51
F-14
B-52
ATR 42/72
Brabazon
Emb 110 bandeirante
Embraer super tucano
Dc8
Dc9
Dc3/C47
Ac47
De Havilland comet
Cessna 172
All Airbus jetliners
Airbus a400
Learjet
Me262
Hindenburg
All Soviet fighter jets in cold war
Fokker 27
Fokker 50
Fokker 70
Fokker 100
Piper
Cessna caravan
Cessna citation
And many more

Sr-71, XB-70, XF-11, F-117, B-36

F-105D and B-52

WW2:
Bf-109, Me-262, P-51D, B-17G, B-29, FW-109
.
Cold war:
F-14, Foxbat, SR-71, F-104, F-4 phantom

F-14 Tomcat, or MiG-25 Foxbat

Most favorite: F-15 series.
Biased favorite: F-14 series.
2nd favorite: Flanker series.
Stealth favorite: Cy-57 Felon.

The rest of the list is in my bio.

Piper Tri Pacer and Cessna 172H

A-29 "Super Tucano", FW-190, BF-110, Dauntlles and finally, F-15 "Eagle"

B-36, or the F-22
.
However, the Cessna 337 is the easiest for me to obtain, and I love it's design

A-10. The thing is beautiful.
My favorite civilian aircraft would probably just be your average two seater Cessna.

F-22A Raptor
Enough so that it became the basis for my "Personal Aircraft"