1. Adele: Adele released her highly anticipated sophomore album, "21," in 2012. The album was a commercial success and critical darling, winning numerous awards including six Grammy Awards, including Album of the Year and Song of the Year ("Rolling in the Deep").
2. Taylor Swift: Taylor Swift released her fourth studio album, "Red," in 2012. The album was another commercial success and included hit singles such as "We Are Never Ever Getting Back Together" and "I Knew You Were Trouble."
3. Bruno Mars: Bruno Mars released his second studio album, "Unorthodox Jukebox," in 2012. The album produced several hit singles, including "Locked Out of Heaven" and "When I Was Your Man."
4. Carly Rae Jepsen: Carly Rae Jepsen rose to international fame with her hit single "Call Me Maybe," which was one of the best-selling singles of 2012.
5. Gotye: Gotye, an Australian singer-songwriter, gained global popularity with his song "Somebody That I Used to Know," featuring Kimbra.
6. Psy: Psy, a South Korean singer, achieved viral success with his music video for "Gangnam Style," which became one of the most-watched videos on YouTube in 2012.
These are just a few examples of notable singers who gained attention and success in 2012. However, it's worth noting that music preferences vary widely, and different individuals may have different opinions about who the "best" singer is.