the first one is correct .喜欢的东西若可数要变成复数.
he likes oranges
he likes eggs
参考资料：my knowledge
要加``
apple是可數名次
泛指的時候就要加
如果說他喜歡那個蘋果不用
这个问题正好是我在考试前向学生强调的:Jenny likes oranges.她喜欢的是这类水果．而不是一个橘子．
应该是He likes apples 吧
apple可数 应该加冠词或复数
he likes apples!
she likes bananas.
he likes grapes.