I would recommend the Tier II T18 TD for this job. It boasts massive armor up front, which is hard to deal with for newbi... I mean newcomers, it has excellent speed, and excellent rate of fire (buy the attack upgrade package for it). Try to make the SPGs in your match high priority targets as well, as if you manage to get to them, they will be free kills for you. Play aggressively, but don't let yourself get flanked, always face your target directly and you should be fine. I got the achievement with this tank in my first match attempting it and it pops during the match.
For ease of reading, here are other tank suggestions from the comments:https://www.trueachievements.com/ill+wayn3.htm
"I'd recommend the T1 Heavy for heavy tank minded players or the M4 Sherman if your medium tank minded. Obviously maxed out upgrades help drastically but definitely not needed. Comes down to slight luck but if you get into a game with tier 3's then it should be relatively easy to whittle down enemies and stay alive long enough to destroy 4 tanks. Just use your environment to your advantage and only 'rush' if your needing those last kills and the game is winding down."KingCrimson220
"Personally I got it on my Sexton I (U.S.). So easy, so fast firing and occasionally one of the lil pesky light tanks holds still long enough for me to drop a shell on em.
Also...if you use Arty for this (it's possible...I've even got Top Gun medals with Arty both low and high tier) you can even get the "Boom Goes the Dynamite" achiev as well. "Cubivore
"The M4 Sherman should definitely be mentioned in this solution. Achievement-minded people will get that tank eventually for the Sherminator achievement, and with the derp gun you can effortlessly 1-shot any tier 3, most tier 4 and even some tier 5 tanks. It's the tank I got the achievement in and it took only 2 games."Chameleon314
"The T1E6-X, a T2 tank that was given out for free, is a beast!"