I also like boonies, I have one in AOR2 and want to get one in Multicam, I find them very comfortable and useful. Ball caps are also good.
Sure, helmets can be very useful, dont own one at the moment but I used to. Especially indoors at CQB games, getting hit in the head hurts a lot more then just a sting to you arms, legs, chest ect. They can also be used to attach a light, comms and a red v light or strobe for indicating you've been hit.