I honestly, ADMITTEDLY, enjoy many books that could be labeled "young adult".
When I read, it's only for fun unless it relates to business. For fun, I just want to be entertained, and I really do not want to think too hard.
I've enjoyed all of the Twilight books, but a lot more than them, The Host, also by Stephenie Myer. It was easy to follow, but had a lot more depth and apappealhan the Twilight books, IMO.
Part of why I enjoy some "teen" (a/k/a "young adult") books is that they're just flat out easily entertaining.
I think if someone who likes that genre has not already looked into Janet Evanovich's "Stephanie Plum" series, they will probably like them, too. AS WELL AS anything by Molly Harper (light, easy to follow, and fun!).
Happy reading! It would be a hard order for me to come up with a more enjoyable hobby short of horses