Ok this may already have two answers but i enjoy doing these questions and i have some more to offer
Scizor
Ok its been mentioned before but just mentioned, not gone into detail.
This is your perfect pokemon.
It has great atk and base 100def and 80spdef along with 70hp which is great paired with its typing making it a great counter for many pokemon, being able to sweep entire teams.
It has low speed which is easy to make up for with bullet punch which is a must on all scizors as it has priority as well as gets stab and technician boost giving it 80 power.
It can run many sets including Choice band, Swords dance even a defsive set.
I personally prefer a swords dance life orb set giving it around 1028 atk which is deadly with a move that hits most types neutrally as well as getting priority.
According to smogons latest usage stats for april scizor was used on around 35% of teams in ou and 8% in ubers showing how powerfull this pokemon is.
Escavalier
Ok great atk and defs to be proud of making this guy an amazing tank, unfortunally its movepool is not as impressive.
Same typing as scizor just with better defs makes this guy awsome but just like scizor it cant take a fire move so be carefull.
Terrible speed, that is what you asked for.
Stab Megahorn really hurts and can rip a team appart.
Iron head is also powerfull and has a chance for flinch, unfortuanally unless in trick room it isnt the easyest to flinch an opponent.
It works great in trick room and has access to moves like swords dance.
Though if your using uu chandeluere could be a problem.
Hippowdon
Great hp base 112 atk worthy of being mentionable, and good defs makes this guy a great wall as well as phazer and i have also used him sucsessfully as a offensive tank in my hail team.
Ok you may be put off by its sand stream but in dream world it has access to sand force so you dont get damaged by the weather.
I love this ability on him and hes the staple of my hail team as it has access to rocks and the power to wall and kill the opposing sand team a hail teams biggest threat, its sand force ability gives it a 30% atk boost on certain moves.
It works eaqually well in sun loosing its water weakness and can be used for the same reasons.
But it has stealth rocks and healling moves such as slack off.
Stab earthquake and other coverage moves like ice fang counter the all so common dragonite and other threats.
All in all its a great pokemon.