Hitmontop

Type Tier
Fighting UU
Statistics
Stat
HP
50
303
Atk
95
288
Def
95
288
SpA
35
168
SpD
110
318
Spe
70
238
Name Item

Physical Attacker

Leftovers
Moveset
~ Hi Jump Kick
~ Curse / Rest
~ Counter / Return
~ Hidden Power Ghost

Look familiar? Hitmontop is played much like Hitmonchan, but better. Counter is a more likely route given that Hitmontop has better Defense. Curse can work nicely because his Special Defense is very high for a Fighting-type.

Other Options

Hitmontop can use Rapid Spin if you really need it that badly. But other than that, there's no good or useful alternative option for it.

Opinion

Hitmontop has higher Defense when compared to Hitmonlee and Hitmonchan—pity it doesn't learn any useful moves. It's strictly an underused Fighting-type, since Primeape, and even Poliwrath, are better.

Counters

Poison and Flying Pokémon resist Hi Jump Kick and aren't overly damaged by Hidden Power Ghost, so they can gradually wear Hitmontop down. Psychic-types kill Hitmontop much faster, but generally are hit decently hard in return by Hidden Power Ghost. Pokémon with a reasonable degree of physical durability will trump Hitmontop, as its attacks aren't particularly powerful. Very strong physical attackers will also work.