Billbine (Under Daikumaryuu), Orgun (Riding on a Giant Fist above Big O and Talisman and left of Weissritter) and Great Zeorymer (to the right of Eva-01 and under the right gun of ARX-8 Laevatien ) are also in the picture.
I recognized the gun of the mecha that comes out in the intro to Armored Core 2 so I added a note. Also I think the one next to Gurren is the Fire Valkyrie? Gonna add a note to two more I see but can't quite think of the name of them.