Interests. And instead of "different opposite", you should choose only one of those adjectives. "Some friends have different views and interests." or "Some friends have opposite views and interests." The first option (with "different") sounds better to me as it is not as strong and is more natural.

interests

Interests

Hmm. You are mixing two statements that are not parallel. So, you can't say 'opposite....interest/s' because it doesn't make sense. So: "Some friends have opposites views and dissimilar interests...." or some such. It still sounds a bit odd and will depend on the context.