Spain
-The widowed Joanna the Mad 1479
-Eleanor of Austria 1498
-Margaret of Austria 1480
-Joanna of Naples 1479
France
-Anne of Navarre 1492
-Claude of France 1498
-Margaret of Angouleme 1492
who is the best alternate wife for him?
1) Juana of Castile - too old for Henry, but considered for his father's second wife.
3) Margaret of Austria - again, too old. Plus, there's the awkward little fact that she told her dad after hubby no. 2 died she'd never marry again.
4) Giovanna of Naples - too old for Henry, considered as his father's second wife. Better option would be her cousins, Isabella or Giulia of Naples (closer in age to Henry, born in the 1490s)
1) Anne of Navarre - right age group, and until her brother has kids, heiress presumptive to the d'Albret-Foix inheritance of Navarre. Could cause 100YW 2.0
2) Claude de France - unlikely that she will marry Henry unless her father has a male heir by Anne of Brittany. Since any other wife means that England once again owns land in France.
3) Marguerite d'Angoulême - a serious contender, much like Eleanor of Austria.
Other candidates to consider:
Bona Sforza, duchess of Bari; Françoise and Anne d'Alençon; and Germaine de Foix. But, again, depends on when Henry will be marrying (after Arthur's death, before his father's death, after his father's death) and what the political situation is (is Henry prince of Wales, or is he still simply duke of York - i.e. Arthur has survived or left a son; who is England looking to make nice with etc).