Opinions are personal, but since you asked:

1st by a mile -- TT .46 Pro -- outstanding quality, power to match the FX & AX, trouble free tuning & operation, long lasting, great price
next-- either the OS FX or AX, take your choice
next -- LEO .46 Pro, solid quality at an outstanding price (but not quite as powerfull as TT & OS)
next -- Magnum -- good quality & power like the LEO, but a bit more pricey
next -- if you feel lucky, Tower hobbies .46/GMS .47 (same motor) they are cheap & powerfull, but there are lots of duds out there
next -- MECOA .46 Tomcat, identical to the LEO in performance, but costs more & has noticeably poorer quality
dead last by a mile -- OS .46 LA, it runs reasonably well, but it can't pull the skin off a grape & costs too much for what you get.