" GUEST
Date: 15 Jun 14 - 04:18 AM
Which covers, in your opinion, are better than the originals?"

First of all, it depends on your definition of the word "cover". If it means a song the performer didn't write, then which version is "better" is often subjective, but some I like better are:
Billie Holiday's version of Body And Soul
Frank Sinatra's version of Fly Me To The Moon
kd lang's version of Hallelujah
Ramblin' Jack's version of Don't Think Twice

Many times the first version you hear, even if it's a "cover", becomes your favorite, because you feel that's how it goes. Many people feel this way about:
The Animals' version of House Of The Rising Sun
Roberta Flack's version of First Time Ever I Saw Your Face
We 5's version of You Were On My Mind
Neil Young's version of Four Strong Winds
Otis Redding's version of Try A Little Tenderness