Though I don't use it for all my reach builds, my favorite is the Greatspear. 2d6 x3, Reach, RI 10' out of the box. As of CompAdv (as I recall), it works with feats taken for use with other spears, so you don't need to double up. Add feats like Monkey Grip (or the Powerful Build attribute), size boosting powers, as well as weapon enchantments (Returning, extended range, things like Fiery, Shocking, bane, etc.) and it gets ugly fast.
If having spear feats already is the issue, just dip Warblade for Weapon Aptitude or ask to use the retraining rules in PHB 2.
Not bad, though the Dwarven Warpike (Races of Stone) is also an exotic reach weapon. It hads 2d6 damage, ability to trip, can be set against charging for x2 damage, x3 crit, can do slashing or piercing damage, and...if you've got a DM who allows the text from C.Warrior (iirc) about swapping racial weapon proficiencies, may not even cost a feat for you to obtain.
If having spear feats already is the issue, just dip Warblade for Weapon Aptitude or ask to use the retraining rules in PHB 2.