Ripken should be unanimous. Gwynn was excellent, but for a single's hitter, he would have nailed it by hitting .400. Still, he's happy in life and a sure first balloter.
Gwynn may have had a reputation as a "singles hitter," but his sheer numbers were unbelievable. His .338 career batting average ranks him among the top 20 of all time, and was ten points better than any other player in the post-1967 era (Rod Carew and Wade Boggs both hit around .328 for their careers). From his first full season in 1983 to his retirement in 2001, his lowest batting average was .309 -- that includes a five-year stretch from 1993-97 when he hit better than .350 every year.
He also may have had the best season nobody ever remembers -- in 1987, he won the batting title with a .370 average, scored 119 runs, stole 56 bases, and won the 2nd of his 5 Gold Glove awards in the outfield.
If Tony Gwynn had played in New York, they'd have a burial plot set aside for him in Monument Park beyond the left field wall.
Gwynn was hitting .394 when the strike killed that season. He was going up too at the time. I think he would have made it to .400 if not for the strike.