Here is a listing of Sade songs that have been re-made or covered by other artists. So far I have located the following:

I have:

Cherish The Day (J. Spencer) (Blue Moon; MoJazz; 1995)
Cherish The Day (Plummet) (??????; ??????; ????)

Kiss of Life (Ken Navarro) (Smooth Sensation; Positive Music; 1997)
Kiss of Life (Rick Braun) (Yours Truly; Artizen; 2005)

No Ordinary Love (George Howard) (A Home Far Away; GRP; 1994)
No Ordinary Love (Duke Jones) (Thunder Island; CTI; 1996)
No Ordinary Love (The Deftones) (Change (In the House of Flies); Maverick; 2000)
No Ordinary Love (Rare Essence) (Doin' It Old School Style; Rare One, 2001)
No Ordinary Love (Bobby Lyle) (Joyful; Lightyear; 2002)
No Ordinary Love (Chris Botti) (When I Fall In Love; Sony; 2004)
No Ordinary Love (Sherrie Lea) (??????; ??????; ????)

Pearls (David Sanborn) (Pearls; Elektra; 1995)

Smooth Operator (Greg Adams) (Hidden Agenda; Epic; 1995)
Smooth Operator (Mongo Santamaria) (Latino Fiesta; Nascente; 1997)
Smooth Operator (Sanne Salomonsen) (In A New York Minute; ??????; 1998)
Smooth Operator (Pru) (Pru; Capitol; 2000)
Smooth Operator (Jerald Daemyon) (The Jerald Daemyon Group; ??????; 2001)
Smooth Operator (Señor Coconut & His Orchestra) (Fiesta Songs; Emperor Norton; 2003)

Love Is Stronger Than Pride (Herbie Hancock) (The New Standard; Mercury; 1996)

Sweetest Taboo (Patrice Rushen) (Signature; Discovery; 1997)
Tabou (aka Sweetest Taboo) (Les Nubians) (Princesses Nubiennes; Virgin; 1999)
Taboo (Glamma Kid featuring Shola Ama) (Fresh Hits 99; Global TV; 1999)
The Sweetest Taboo (Robin Millar) (Kiss & Tell; NuJaz; 2003)

I've heard (at least a part of) but do not have:

Haunt Me (Sarah Jane Morris) (Blue Valentine; Ronnie Scott's; 1995)
Kiss of Life (Ryo Kawasaki) (Love Within The Universe; One Voice/Vide; 1994)
Kiss of Life (Michael Ross) (The Last Love Letter; ??????; ????)
Kiss of Life (Carol Heffler) (Pull of the Moon; ??????; ????)
Love Is Stronger Than Pride (The King Singers) (Spirit Voices; ??????; ????)
No Ordinary Love (Kenny Lattimore & Chanté Moore) (??????; ??????; 2005)
Sweetest Taboo (Saxman Rick Parma) (Saxman's Coming; ??????; ????)

I've heard of but have never actually heard:

Smooth Operator (Lester Bowie) (Serious Fun; DIW; 1989)

Any help with unearthing any others will be appreciated. The tracks listed above, while not Sade, are mostly quite cool interpretations of the originals. Some are pretty faithful to the original interpretations and some take the songs in entirely different directions. I hope that this section will grow over time.