Here are some of the most iconic and influential R&B songs of all time, in no particular order:

1. "I Will Always Love You" by Whitney Houston - This power ballad, originally written and performed by Dolly Parton, became a worldwide hit when Houston covered it for the soundtrack of the 1992 film "The Bodyguard". It remains one of the best-selling singles of all time and showcases Houston's incredible vocal range and emotional depth.

2. "Let's Stay Together" by Al Green - This classic love song, released in 1971, is a staple of soul and R&B music. Green's smooth vocals and the song's simple, yet memorable melody make it a timeless favorite.

3. "Sexual Healing" by Marvin Gaye - This 1982 hit was one of Gaye's last before his tragic death in 1984. It features a catchy bassline and Gaye's signature falsetto, and is often cited as one of the greatest love songs of all time.

4. "I Heard It Through the Grapevine" by Marvin Gaye - Originally recorded by Gladys Knight & the Pips, this Motown classic was later covered by Gaye and became one of his biggest hits. The song's driving beat and Gaye's soulful vocals make it an enduring favorite.

5. "My Girl" by The Temptations - This 1965 hit is a quintessential example of the Motown sound, with its catchy melody, upbeat tempo, and tight harmonies. It remains one of the most beloved and recognizable R&B songs of all time.

6. "Ain't No Sunshine" by Bill Withers - Withers' hauntingly beautiful voice and minimalist guitar accompaniment make this 1971 hit a standout in the R&B canon. The song's simple, repetitive lyrics and soulful delivery make it a timeless classic.

7. "What's Going On" by Marvin Gaye - This socially conscious anthem, released in 1971, was a departure from Gaye's earlier hits and marked a new direction for R&B music. The song's message of peace and unity is just as relevant today as it was 50 years ago.

8. "Respect" by Aretha Franklin - This iconic feminist anthem, originally written and recorded by Otis Redding, became a smash hit for Franklin in 1967. Her powerful vocals and commanding presence make it a must-listen for anyone interested in R&B music.

9. "Superstition" by Stevie Wonder - This funky, upbeat track from Wonder's 1972 album "Talking Book" showcases his incredible talent as a songwriter, musician, and performer. The song's catchy riff and infectious groove make it a timeless classic.

10. "No Scrubs" by TLC - This 1999 hit from the all-female R&B group TLC became an instant classic with its catchy chorus and empowering lyrics. The song's message of self-respect and independence resonated with a generation of young women and continues to be a fan favorite today.