Please don't be fooled by all the Ads out there selling their "New Method" for Learning Piano or Guitar, in a QUICK, FUN and EASY way ...and that you'll be able to play 1000's of songs in ten minutes just like the "Axis of Awesome" 4 chord song. Which uses a I V iv IV chord progression (in the key of D by the way - so the chords used are D A Bm and G). When Performing live they would play in the key of E (E B C#m and A). (see the chord progression charts below for chords in all 12 keys) 

Now, as brilliant as Axis of Awesome are, it is important to know that they are playing "parts" of songs that fit the 4 chord progression... (as you progress through the courses you'll learn more about the theory along with other common chord progressions). 

It is a great "parlour trick" to play a medley like Axis of Awesome do in their official video below (they actually play 47 songs!).

However, as you can see they aren't performing any of the songs in there entirety (of course) or their original keys - No riffs, No licks, No solos - just the melody of the songs with the "rhythm" that we all recognise!

It should also be noticed that the chords are used in rotation, allowing for the following progressions to be catered for: - 

I V iv IV (e.g. D A Bm G)

V iv IV I (e.g. A Bm G D)

iv IV I V (e.g. Bm G D A)

IV I V iv (e.g. G D A Bm)

Notice how these "rotations' are all the "same" chord progression!

Of course it is great fun to play songs in this way and it is a brilliant way of learning / practicing chords and chord progressions, timing, transposition, rhythm etc. and just being able to jam along to loads of great tunes is great fun - so, this kind of learning certainly does serve a purpose... 

When you know enough songs, you could even begin to challenge friends and family to "ask you to play anything" like Ed Sheeran does below, which I personally find a tad more impressive than Axis of Awesome, but only because it appears 'off the cuff' (and to remember lyrics and melodies of "any" song someone throws at you is a challenge all of its own (guitar in hand or not!).

Rest assured the only way to Really Learn Music and play your instrument well, is with good solid tuition and daily dedicated practice, and with that being said, let's go back and take a look at some of those I IV V songs you may want to "learn" and jam along with as you continue to practice chord changes and improve as a guitarist/musician!