All right, this is my first build.... so hopefully I do okay.
This build works really well for me personally I think just because of the way I play Malphite.
And Usually the match is over before I can even get Banshee's Veil.

Well okay lets get started.

Pros
-One of the best tanks in the game
-Really good farmer
-Really good chaser
-Can tank a lot of damage


Cons
-Item dependent
-Team dependent, if you don't have a good team who knows what to do you will just end up dying the whole game.(when tanking)
-Mana dependent

Clarity, Its just a must for Malphite, you will often see yourself run out of mana.

Ghost, Is really good to catch up to teammates in distress, or opponents running away.

Flash is also a good summoner spell for malphite.

Ninja Tabi, just give you that extra dodge chance, combined with the mastery skills it works really well for me.

Sunfire Cape, is an all tank must have item... it works really well for farming.

Thornmail, I almost always get this. apart from the 30% damage it gives to attackers. it gives you 100 armor wich works really well with your ground slam, extra damage. Works awesome in team fights as well.

Banshee's Veil, Blocks a negative spell, and is a really good for team fights, gives you more survivability.

Randuin's Omen, Really well for team fights once again, and its like the item made for malphite.

I know this doesn't look like much, but this build works very well for me. and hopefully it will work well for you too.