So this is a the build I use most the time for pantheon. I normally get boots then mallet first. Then from there i base it around who I am fighting. Lately it seems like there has been a lot of people playing AP characters (even if they are normally AD characters like Yi or Teemo ) So the above build gives you a high amount of survivability and so nice damage. Since Panth is a burst damage champ, I normally try to keep to hit and run tactics. If you have the money / time trade I would trade out Doran's blade for banshee's veil, but thats just me. Plus my games normmaly finish before I get the blood thirster.

Just my thoughts and opinions. Let me know what you think or if you have any suggestions.