One handed weapon style, sans shield. Whip-fighting, for added anti-optimization.
Disclaimer: This is undoubtedly better with a shield, at least a buckler; I cannot come up with a martial build that isn't improved in some way by making use of both hands.
Okay. Here goes.
Illumian Warblade 5/Shadow Sentinel 5/Kensai 10. STR 14 DEX 12 CON 15 INT 13 WIS 8 CHA 10, or higher PB equivalent.
1) WB 1 - EWP: Whip-dagger
3) WB 3 - Combat Expertise
5) WB 5 - WF: Whip Dagger
6) WB 5/ShS 1 - Combat Reflexes
9) WB 5/ShS 4 - Improved Trip
12) WB 5/ShS 5/Ken 2 - Martial Stance: Daggerspell Stance
15) WB 5/ShS 5/Ken 5 - Vital Recovery
18) WB 5/ShS 5/Ken 8 - Rapid Assault
If we accept the notion that a Tank's primary job is to keep the mooks off the spellcasters, this does that job pretty well. Vital Recovery could be taken earlier to make dependency on the healer a lesser concern.