Which arb is best in general ? i take losartan 50 mg twice daily but it isnt working well. i have heart disease, metabolic syndrome, blood clotting dosorder, stroke , etc?

For your underlying problems, using losartan, am ARB drug, seems to be the right choice. You said losartan isn't working well but in what aspect. A newer, longer acting ARB such as telmisartan, olmesartan can be an alternative. If uncontrolled BP is the problem, then another med such as diuretic, beta blocker, etc. can be added when max dose of those noted ARBs are not strong enough. Good luck.