Depends on the army your are fighting against but my run of the mill standard late army is as follows (exception unhorsed knights)

x8 Portugese Abrequeser (PORTUGESE not reg!)
x4 Unhorsed Knights
x3 Tercio Pikemen
x2 Heavy Horse (chiv knights or the like)
x2 Musketeer
x1 Officer

of course there are exceptions... alot of time ill make a gun only stack

x10 Portugese Arbs
x6 Musketeers
x1 Culverin
x2 Heavy Horse
x1 Officer

against the tims/mongols alot of archers ,spearmen of all types and qualitys and light horse ..all of them spammed in abundance and without regard

theres many other combos tho that im sure are just as or more effective.... few as pretty to watch tho =)