ME1 = Ok above average with some serious annoyances (elevator and driving up slopes). Kaidan and Ashley were annoying as hell so it was nice i could nuke them. Too bad couldn't nuke the both of them. Really, having Wrex, Garrus, Liara and Tali was sufficient to save the galaxy.
ME2 = Fantastic. Great characters, strong story, strong ending, fast paced and turnaround play with Joker. Let down slightly by the forced plot in making everyone leave the normandy. This setup chapter was extremely good, as it allowed ME3 to build on those characters. LoSB was enjoyable and closed a hole with the Liara situation.
ME3 = Fantastic x2 up until anderson bled out (damn bleeder, never bought a jumbo pack). Characters built up from ME2 started dropping. Fantastic x3 with the various DLCs. Multiplayer = amazing longevity. That was the reason for the massive head desk on the 3 colours. Extended if it came out with the original game would have helped but the original ending was dumb x dumb x dumb.