I can think of a few candidates, here they are. Basing it off the most popular types of dragons we see in history/media since technically dragons can look like anything
Draco lizards:

Photo: user Psumuseum on wikimedia
Pros: Has 4 limbs AND wings, very traditionally dragon like shape
Cons: Tiny (fits in hand), wings aren't technically limbs (they're ribs
), can only glide
Olm:

Photo: Arne Hodalic
Pros: Serpentine, very dragon like head shape
Cons: Tiny (school ruler size), amphibian not reptile
Pterosaur:

Photo: user Ghedoghedo on wikimedia (model from Natural History Museum Karlsruhe)
Pros: BIG (biggest at 11m wingspan), can really fly
Cons: The big ones have a weird body shape that reminds me more of giraffe than reptile
This thing (yi qi) (a "scansiopteryid" dinosaur idk if I spelt that right):

Restoration: Nobu Tamura
Pros: Multiple fingered wings
Cons: Tiny (regular bird size), likely couldn't achieve true flight
Cast your votes... or (please) enlighten me of other candidates
Draco lizards:

Photo: user Psumuseum on wikimedia
Pros: Has 4 limbs AND wings, very traditionally dragon like shape
Cons: Tiny (fits in hand), wings aren't technically limbs (they're ribs

Olm:

Photo: Arne Hodalic
Pros: Serpentine, very dragon like head shape
Cons: Tiny (school ruler size), amphibian not reptile
Pterosaur:

Photo: user Ghedoghedo on wikimedia (model from Natural History Museum Karlsruhe)
Pros: BIG (biggest at 11m wingspan), can really fly
Cons: The big ones have a weird body shape that reminds me more of giraffe than reptile
This thing (yi qi) (a "scansiopteryid" dinosaur idk if I spelt that right):

Restoration: Nobu Tamura
Pros: Multiple fingered wings
Cons: Tiny (regular bird size), likely couldn't achieve true flight
Cast your votes... or (please) enlighten me of other candidates