Mac (more of a past success. not that big currently anymore) and iPhone. That's it
There is a reason Apple is called a one trick pony
iPod was the base for iPhone and died with the iPhone
iTunes is a side product, nothing unique and nothing people could not live without. some people still hate it and other still don't even know it. especially today, when your iPhone is synced via cloud and you don't need iTunes anymore
iPad is not a big success and just a bigger iPhone. side product, too if you want to name it that way.
Just like Microsoft has 3
Windows, productivity software and Cloud
Amazon has 3
ecommerce, cloud and digital content
Google has also 3
Search, Android and services