I love the character of her voice. There are (were) other sopranos out there, but her voice had such a wonderful quality and richness. Others are ok, but come off to me as a bit too shrill.
For me vocal character is key. Pavarotti was a magnificent tenor, and he could hit those notes with accuracy and clarity. But I prefer the warmth of Bocelli's voice over his, even though he lacks that accuracy and throws is that occasional (almost imperceptible) flat.
I sat 12 feet from Pavarotti at Christmas dinner recital for Houston Grand Opera patrons. I was also lucky to hear Susan Mechser and Dame Joan Sutherland sing the duet from Norma. Brought the house and got a standing ovation for 30 minutes.
The Three Tenors is on my Christmas rotation.