I figured that when it came to MPs and military service, the Tories would lead the pack, and I was right. But the runner up was a bit of a shock.

Conservative MPs who have served: 7
NDP MPs who have served: 2
Liberal MPs who have served: 1

(note I moved Wajid Khan over to the Conservatives, although he was elected as an Liberal originally)

H/T to my friend JP for this one.