There's something magical about Delphi. Okay, it IS extremely touristy on the main drag, but the grounds of the Temple of Apollo and the Temple of Athena are simply awe-inspiring.
The Delphi Museum is also excellent.
The town is very nice to stall around, the views area amassing! The archeological site is worth the visit, do not miss the museum.
Don't go all the way up to the stadium, not much to see for a steep climb.
Delphi is a very very small village , i would only recommand it for relaxation or shopping. Maybe for hiking too.
For the rest i wouldnt go there. Absolutly must see is the Apollon hill. The museum is also worth visiting it. Its cheap combined to the Apollon entrance ticket.