I've gotten a couple since I've joined the Marines. 2 of them I got when I was in Australia. Being into militaria and history they've all been American Traditional accept for one. One of the pieces I've gotten is a patriotic flash art from 1940. I plan on getting a lot more while i'm in. The regs though make it hard to get any good size pieces on your arms or legs though.
Be very careful with this...while tattoos you get under current regs will likely be grandfathered if regs change, they can still be very limiting. Most SDAs now have very strict rules on tattoos that exceed the institutional regs, which is authorized since they require additional screening. A lot of forearm tats of any kind pretty much make you ineligible for recruiting or MSG (you know, jobs where you have to convince the parents of 17 year olds to trust signing the contract, or represent the institution internationally). Ditto for Presidential detail. Pretty much anything in the public eye. Successful SDAs are looked at very heavily when up for promotion to SNCO ranks...in peacetime (which we're technically in), they're almost a requirement. Ineligibility for SDAs, voluntary or HSST, can result in a 'P'.
Additionally, warrant officers and officers have much more stringent regs. Even if your current tats are accepted by those programs, if the regs change, your grandfathering will not extend to switching to the shiny stuff.
Also, READ AND UNDERSTAND THE ORDER. The popular belief is that if your hand covers the ink, it's good. That's a MYTH and only applicable in certain instances, if all other criteria is met. I've watched a half dozen Marines get processed out because they listened to the LCpl underground and sea lawyers.
Moral of the story...tattoos, even in regs, can severely limit your career options. It's why I stopped getting extremity work after they tightened up the regs in 2007. Due to the regs, I can't even finish the work on my leg, as the grandfathering only applies to what was done at the time.