The best characters in novels don't have common names:
Caballo Blanco, Barefoot Ted, and Bonehead (okay, not a novel, but it halfway reads as one.)
A Dave Smith or Sally Wilson doesn't really strike a chord with readers. It may be that the unusual names are designed to do just that--catch the readers' attention and, by proxy, emotional interest and investment.
There's a bit in The Life and Opinios of Tristram Shandy, Gentleman (another odd name) where Tristram's father Walter is nearing obsession over what to name his son, believing it to set his course and fortunes for life. He believes that to name a child Judas is to curse him, and Tristram is the worst possible name imaginable. He comes up with the one name that will satisfy: Trismegistus. He gives the name to the chambermaid Susannah who runs through the house to where the baby is being born only for her to forget half the name and sputter out variations of the name. The priest believes that she is trying to say Tristram and christens him such, much to Walter's dismay when he finally arrives. (The birth scene in the film A Cock and Bull Story is hilarious.)
But my favorite author for odd names is Thomas Pynchon. Here is just a sample of some of his gems:
Larry "Doc" Sportello
Who are your favorite characters? What do their names do for you?