Domain Should Be WWW or Without WWW! A Short Insight!

It might be a controversial topic as both versions can be debated. But I will depict my opinion.
As per my view without www is better because:

1. You save 4 characters. Yes, www.=4. In this way, you can place more characters in the permalink of an article.
2. It looks good when you make a backlink for a naked domain. You can write example.com which looks great as compared to www.exmaple.com. Your anchor text looks more natural.

Ok! It means you want to say you should only buy a domain without www? Right? No, No! Some domains look great when you write www with them; others don't.
You can judge the domain is looking good or not if you're regular visitor of websites. As you can see moz.com, majestic.com, ahref.com are all without www. Because these are the SEO companies they know the value of saving 4 characters and other getting backlinks with a good anchor text distribution.

The choice is yours! Otherwise, there is no ranking disadvantage in selecting any of the version. Both work well in term of ranking.