This album is, unfortunately, not a 'best of' compilation and is exactly what it claims to be - a collection of the band's greatest hits. There's a big difference between the two, but many people make the mistake of thinking the titles are interchangeable.
Allow me to explain...
A greatest hits collection is an album containing the songs that were HITS (entered the official charts due to record sales) that sold the GREATEST amount.
A 'best of' collection would be an album containing the songs considered to be musically or lyrically better than the majority of the band's other work, regardless of commercial success.
If this album were a 'best of...' then it would contain songs like Meaning Of Life, Dirty Magic, Jennifer Lost The War and Million Miles Away, but it's not; it's a Greatest Hits, so what we have here is a handful of songs that were the most commercially successful. This means the album is full of the band's most radio-friendly material: Pretty Fly, Original Prankster, Why Don't You Get A Job and others of that ilk. Over-produced cheesey pop-rock, basically.
As an introduction to the band it cannot be recommended. Yes, you do get a rough idea how their sound has changed between 1995 and 2005, but it's not a good representation of the type of punk song that The Offspring tend to do very well. In fact, the only real Offspring-esque track on the album is 'All I Want'.
For a proper introduction to the band I would suggest the albums 'Smash', 'Ixnay On The Hombre' and 'Days Go By'; all of which can be purchased for a few pounds/dollars these days. Together those albums will give you a better idea of the type of music the band made before and after the silly 'Pretty Fly' phase that this album was designed to cash in on.