OK, with the big 4 of Matty, Seanez, Romano and West covered, here's how I see the other top candidates.
Alex Ramirez gets consideration because he was the rare power-hitting 2B/CF. He's certainly a little short in the awards department - just 3 All-Stars and 2 Silver Sluggers. But he did top 60 homers twice and 50 another 4 times (and 480 total). I think he's just good enough on the strength his power game.
I put Rico Nunez right about on par with Ramirez. He wasn't quite the hitter Ramirez was (.894 career OPS vs. Ramirez' .964), but he was a pure SS for most of his career, and those 417 dingers are pretty impressive. Add in the 3 GG's at SS (doesn't sound like much, but the way fielding stats go it's really hard to do) and he may have a little bit better case.
Steven Vaughn's claim rests on his 3 Cy Young's (in fact, he won the first 3 AL CY's), which in turn rest on his win totals. He was a game-winner, for sure - almost 18 a season for his career. Here's my big problem with Vaughn: his contemporary (and teammate for 5 seasons in OAK) Thomas Sparks was a better pitcher by every qualitative measure (ERA, Whip, OAV, OBP against, and Slugging % against) over their entire careers, and I just can't see Sparks as a Hall-Of-Famer.
I'm going to go with Nunez with my 5th vote.