Could you let me know the word count of some common books and novel-length guidelines?

Some resources (like NaNoWriMo) say novels can be 50,000, some books say 80,000 is average, and I just read an online article that said 120,000 is the upper end of the "comfortable range for beginner novelists" that publishers will accept.

What are the real word count guidelines (in particular for YA fiction)?

BQ:
If possible could you give my examples of common books I may know and their word lengths to get an idea?


Thanks