With a Golden Saint in Azura's Star, what are the best enchantments I can put on this sword?

My favorite is Absorb Health on Strike, the largest amount it will take. It's a matter of taste, of course.

This.
Unbelievably powerful.

I've also done cast-on -strike fire, frost and shock all combined. Almost as good, but with the absorb health you're about unbeatable.

Absorb Health on strike. You will meet foes in the expansions who reflect spells, and if this one is reflected it does no damage.

Question's answered so I'll do a minor derail.

I found it to be an excellent idea to enchant one of those with fortify luck 400 points on strike for 2s when fighting Gaenor. Summon a couple Golden Saints to be meat shields for his abuse and yours, get it going by hitting one of them, proceed to stop missing every time you swing at Gaenor.

True as long as you don't have Morrowind Code Patch installed. MCP fixes Reflect so that Absorb Health gets reflected too.

I read on a similar thread, someone put Absorb Fatigue on Strike.
Which is a really good idea.

Charm 50 p0ints when strikes