Look into the armies of the 1470's, 1500's and 1600's. They were heavily influenced by the Roman Way. There is a "revival" (with the Renaissance, pun intended) of the strategies and works of Caesar, Tacticus, Vegetius and Maurice (Strategikon)
The development of the Pike Square in the late 1400's into the 15 and 1600's is nearly directly taken from the Phalanx as well as Alexander the Great's tactics and formations. (look into the Swiss Pike Square, and the Battle of Grandson 1476 among others)
The Swiss and Dutch were big proponents of "Roman" tactics in the late 1500's-1600's, I believe one famous general went by the name of Maurice of Nassau in the early 1600's (not to be confused with the Strategikon written by a Maurice in the 5th century!), and was also influenced by the writings of Aelian (variations on spelling occurs), Livy and Polybius. There is an Illustration of a "Target and Shield Man" in the 1625 manual "The Exercise of Arms"...You can see this illustration in Osprey's "Republican Roman Army 200-104 BC" Men At Arms 291, Page 23. His posture is very close to that of the Mainz relief showing the Legionary in "fighting stance"
http://www.romanarmy.com/rat/viewtopic. ... ght=aelian
Also, the Italian fencing master Giacamo di Grassi mentions "Roman" tactics in his "True Arte of Defense" ca. 1570, mentioning that Thrusting is the prefered and best tactic to use, as a slash takes too long and is easily seen by your oponent (I'm paraphrasing here) ~ Much as Vegetius writes in the Late Empire that 'thrusting is the best attack, taking the slash on the shield and thrusting into the oponent is most effective' (again, paraphrasing)
There is also a manual currently being researched and translated, a Fechtbuch by a Paulus H Mair (ca. 1530's) that mentions that the Poleaxe and Quarterstaff was developed by the Romans...Which is a little awkward, but I mention it because there is sometimes the "fantastical" Roman influence...Dare I say "Romanesque".
In more modern terms, one of the easiest to see is Napoleon in the 17-1800's. Supposedly he directly took the idea of the Roman Aquila Eagle standard and designed his own Eagles for his armies. The Curaissiers and Carabiniers of that timeperiod also had bits of Roman like stuff on thier armor and helmets - the horse "ponytail" crest you see on Cuirassiers and on the British Royal Guard (Palace guard? sorry I forget the proper term), can easily been seen from Late Republican ponytail crests on Montefortinos and Coolus helmets, such as the Ahenoborus relief.
In the American Civil War, there is Romanesque styled swords that were worn by some Artillery crews, among other bits here and there.
Of course there is the revival of Roman stuff in World War 2, with Mussolini and the Fascists (name from the Fasces, the bundles of rods and axe symbolizing Roman Law and Authority), as well as his dreams of re-inventing Rome and the "New Empire".
Also take a look today at modern Police Riot gear and tactics - You'll see the use of large shields (now out of plexiglas and whatnot instead of wood and leather/felt), and helmets that have neck guards. Interesting similar to Legionary gear.