Originally Posted by The Gift Horse
ROA is the only mana item you should be building in your core. Banshee's, Frozen Heart and Lichbane hugely situational, and you shouldn't be buying any other mana item on him.
Lol, I would completely disagree with you. I definitely build RoA, Frozen Heart, and Banshee's every game with Singed. His passive is actually very useful, compared to other champs. You should take advantage of his passive and make him even harder to kill. If you really wanna be "that guy", you could build Archangel's staff and get 350 health off of it and get mana regen and a bit of AP.
When I play Singed, my usual end-game build is Merc Treads, RoA, Frozen Heart, Banshee's, Force of Nature, and (insert any item you feel necessary).
I go Magic Pen marks, flat armor seals, and flat magic resist glyphs. I also get 3 Move speed quints. I go 1/21/8 and with no boots at lvl 1, you have 350 move speed; that's almost like having Boots of Speed on an AD champ, with his ult and ghost, you move faster than most champs can, even with Move Speed 2 boots when you don't have any.
Singed is definitely one of my favorites and it kills me when people say not to build mana items on him. *le gasp