Eskarlin Vasquez, OF - Vasquez is a right fielder from the Dominican Republic with a very strong arm. Potentially a five-tool prospect, he has good power and many scouts believe he's the best position player available. Back on May 17, Frankie Piliere of MLB Fanhouse said the Giants were the favorites to land him.
Vicmal De La Cruz, OF - Others might think De La Cruz has the best bat of anyone in this class. He is a potential five-tool prospect with maybe the highest upside of anyone on this list.
Phillips Castillo, OF - Castillo is another outfielder from the Dominican Republic who's calling card is his power. He could be the best power bat in this class and he could come cheaper than others.
Martin Steylon Peguero, SS - Tools, tools, tools. That's what this guy is all about. He's raw and athletic but supposedly has huge upside and power potential. A power bat at a premium position sounds good to me. Too bad the Giants never go after raw hitters, probably because they know they are too incompetent to develop them.
Elvis Sanchez, 3B - Sounds a little like Pablo Sandoval. He's improved his body a lot but still may have to move off third in the future. His main tool is POWER. He's got lots of it, and I yearn for a time when the Giants will have a legit power hitter.
Luis Heredia, RHP - Maybe the best pitcher from this class of free agents, this kid is only 15 years old. He's already 6'4" and is extremely projectable. He'll be tough to sign though. His team in Mexico owns his rights and according to MLBTradeRumors, the Giants, Pirates, Dodgers, Yankees, Blue Jays, Mariners, and Rangers are all interested.
Geronimo Fransua, LHP - He's thin and projectable like a lot of the guys on this list. His velocity is already in the low-90s and he may have room to fill out and reach up into the mid-90s. He's also got some decent secondary pitches that will improve over time.
Luis Abad, RHP - Abad, also from the Dominican Republic, is really interesting because he's another pitcher with high upside. He's 160 pounds and can run his fastball up to the mid-90s with extremely good movement.
Jorge Feliz, RHP - Feliz throws in the low-90s with an already good curveball. These prospects don't normally have plus secondary pitches, so Feliz could be interesting.
Roughned Odor, SS - This guy is mostly on the list because of his name. Besides his awesome, or terribly unfortunate (depending on how you look at it) name, Odor is expected to be a high average hitter who can stay at shortstop. Those guys are always nice to have.
The farm system is fairly weak right now, so the Giants could use some young talent. Expect them to sign one or two guys from this list.