Hobbies and interests are definitely not the most important details on a CV. And they will most likely not change the recruiter’s mind if your skills and experience are not impressive.
That said, some employers are not interested in your pastimes outside of office hours, while there are many others who believe it helps to give them an insight into your personality.
Still, the decision whether to include your hobbies in your CV is yours. If you will, consider what your hobbies may say about you to an employer. For an effective CV, ensure your hobbies back up everything the recruiter has read so far.
Finally, always resist the temptation to embellish (or tell a white lie). Stating your love for Chess to try and make yourself appear smart or brainy could lead to problems if the interviewer turns out to be a Master Chess player. You’ll look stupid and untrustworthy if you can’t differentiate your Rook from the Bishop.