I've taken pike up as my primary weapon. My preference when it comes to combos is Jab, Thrust, Lunge, (add Slam, depending on the enemy). The slam does pretty nice impact, but is terribly inaccurate. I count on the lunge for most of my damage production. It is the only high-powered attack available to pike users, unless you go with the ngalio, which is a slicing weapon.

I am a tog barbarian, and find that HP armor and an arm-worn shield best compliment my weapon choice. My low reflexes combined with the vulnerability that comes from lunging make armor that can take turn the punishment away a must. Shield, well, that's just an obvious choice, though the balanced boar spear and my forged s/l/l average strength pikes work alright for parry. The pike is very heavy and WILL take you 6 seconds to execute every maneuver. I don't recommend the s/l/l pike to other who don't:

A.) have enormous stamina
B.) happen to be berserk-crazy barbarians