I don’t think which I heard first has a whole lot of bearing on my tastes, but if you want examples:
I heard Massive Attack’s version of " Hunter Gets Captured by the Game" long before I ever heard the orginal motown version (by the Marvelettes?) , and I can’t believe how much better Massive’s version is.
" Love Song" I like equally by The Cure and 311. Tori Amos’ version is ok too. I heard them The Cure/Tori/311
While on the other hand, I hate " Boys Don’t Cry" by The Cure and Oleander equally, and I heard the Oleander version first.
I like Toad The Wet Sprocket’s version of “Hey Bulldog” better than the Beatles version, and on the same cd I like Kula Shaker’s version of “Hush” equally to the Deep Purple version, and Type O Negative’s version of “Summer Breeze” ten times as much as the Seals and Cofts version. Of those, “Hey Bulldog” is the only one I heard the cover first.
I like “Strange little girl” by Tori Amos much better than the orginal, though I can’t recall at the moment who it’s by (the stranglers?). I know I heard the Tori version first. Back to the Beatles… I didn’t know for years that their song “A Taste of Honey,” which is one of my favorites by them, was a cover. I was underwhelmed by the orginal, which I can’t for the life of me remember who it was by.
I like Dishwalla’s version of “Policy of Truth” maginally better than Depeche Mode’s, and I heard the DP version first. On the other hand, Veruca Salt’s cover of DP’s “Somebody” is kind of creepy, and I don’t like it as much as the orginal. I have no idea which version I heard first, though.
Then there are a couple of songs I didn’t really know I knew until the covers came out. " It’s My Life" by Talk Talk isn’t as good as the No Doubt version, and “Smooth Criminal” by Micheal Jackson doesn’t have the energy that I love in the Alien Ant Farm version. Since they rang very faint bells when I heard each cover for the first time, I must have heard the orginals first, back when I was little.