Definitely liking the left and mdidle ones. If only the one in the middle had a smaller pair of combat arms in the front, then it'd be pretty close to perfect: small arms to attack, large arms to defend
Definitely the first one. I like the huge, imposing look of the middle guy but as Bracey pointed out it looks like it would be very slow and awkward. Given the placement of the drills I don't think it could even use them in combat, unless it were already underground and was attacking from below. I like the top half of the far-right one, but the transition between it and the insectoid lower half is way too abrupt. Instead of looking like a big bug it strikes me as the top half of a biped crammed onto the lower half of an insect. The first, more traditional one just happens to be the most natural and effective looking of the bunch. Really fantastic artwork all around, though, these look fantastic!
Number one, I like the combination of Mimic roach andGeneral Grievous vibe I get from that guy. The middle one looks cool but very cumbersome for fighting. Big arms need a lot of room and would tend to telegraph every blow. The lobster is pretty interesting and I like the combo of pinchers and drill bits. I think Im gonna vote number 1 as my favorite though.