High performance organic thin-film transistors were demonstrated based on a cheap, commercially available organic semiconductor, titanyl phthalocyanine (TiOPc), in its alpha-phase structure. The high performance is due to its ultra close pi-stack and favorable edge-on molecular orientation in the films. The high performance, the remarkable stability, low price, nontoxicity, and commercial availability of TiOPc suggest promising prospects in OTFTs.