I hope I can have 3 as each covers a particular role
First up is the Fokker 50. I have a real attachment to this aircraft as I used to use these regularly for short hops between Norwich and Amsterdam. It's not the prettiest bird around, nor is it the most comfortable, but it did instill a feeling of solidity and reliability. There's something reassuring about seeing the props spinning, and due to the wings being above the cabin, seeing the undercarriage come down.
Second, in terms of combat aircraft I don't think anything has come close to the flexibility of the F/A 18 Hornet. It's equally at home with carrier or land based operations. Admittedly it is a "jack of all trades, master of none", but where it doesn't master it still does a damed good job.
Third we have the general workhorse, and unsung hero the Douglas DC-3 (Dakota). First introduced in 1936, it's still being used in some parts of the world today. In its era it was unequalled in terms of the roles it could play. From passenger to cargo to military transport it truly is a legend.