For Portugal, in recent memory.
1999, Azerbeijan away..1-1. Could it get any worse?
2002, Finland home....1-4, oh the shame.
2004, Leichtenstein away........2-2.
I think that there can be few contenders for such a shameful result.
As for the best result, maybe that was acheived in the '80s, when we won 1-0 away to Germany (Stuttgard?) to become, I believe, the first team to beat them in a home qualifying fixture.
So, come on, don't be shy, whats the worse your country did?