Sungyeol of INFINITE is very, very pretty. He would be a prime suspect for some plastic surgery, but he basically looks the same in his pre-debut photos as he does now. He even still has the same sad eyes. The only difference I can see is that Sungyeol wears a lot more make-up these days, his skin seems whiter, and he probably had his teeth fixed. None of these things constitutes plastic surgery.
Before and after pics