I'm not really into tsunderes who are like, “I love you, but for some reason, not only will I never tell you, I'll also treat you like crap for no particular reason.”
The ones who are like, “I love you, but you won't hear it from me because something happened to me and I have to navigate this as if it were thin ice” are okay, and there are some I actually like.
Then there are some who are classified as tsunderes but not quite—the ones who start out with feelings and an attitude clearly against you for X reasons, but little by little open up even though they flat-out deny it at first. Those are fine.