Aruba or St. Lucia?

My fiance and I have narrowed our honeymoon location down to Aruba and St. Lucia. Can anyone recommend resorts in either?

We're not big drinkers, so it doesn't necessarily need to be 'all-inclusive,' and we're not really bar/club people so it's okay if there's not a lot of nightlife. We're really looking for a nice, low-key place with a beach that's not going to cost us an arm and a leg. I'm getting married in October 2009.

Thanks!