If we're being honest with ourselves, the Reds really don't have a true CF in house at the moment. Ryan Freel's a hard working utility man, not a natural CF. Norris Hopper's a bench player. Josh Hamilton's a corner OF who can hold down CF in a pinch. Chris Dickerson is a true CF, but he doesn't hit well enough to be more than a role player. Jay Bruce, by all accounts, is the second coming of Larry Walker, which means that he'd be an all right CF, but that he could dominate in RF. I say put him where he can dominate.
That means if the Reds truly want a CF then they're going to have go outside their walls to find one. I'll kick it off here with some names, but there's a lot more guys than the ones I'm going to list and I'm curious to hear what others think about various candidates.
Andruw Jones - He's one of the younger free agent CFs (30) and he ranks #1 among CFs in RZR (.931, though do not take that as blanket proof that he is the best overall CF out there). Yet he's also having his worst season at the plate in a decade and he'll be ridiculously expensive.
Torii Hunter - He's 32 with power and still has some range (.897 RZR). He's lost a step around the bases and he's never been all that good about finding 1B. Also stands to be a budget buster.
Aaron Rowand - His timing is impeccable, OPSing roughly 100 points above his career average in his walk year. Whether he can continue to do that is an open question, but less so in a small park like the GAB. He plays hustle defense, but his RZR is usually on the low side (.854 this season). He might become the "in vogue" selection.
Mike Cameron - He's been incredibly steady the past nine seasons, great glove (.895 RZR), good wheels, good power, good eye at the plate. His numbers usually aren't eye-popping, but that's largely because he's played in the best pitchers parks in baseball. Put him in a hitter's park and you could get an .850+ OPS player for a couple of seasons. The downside is he's 34, though he keeps himself in tremendous shape. Probably the least expensive of the top free agent CFs.
Corey Patterson - Patterson's seriously OB challenged and his power comes and goes, but he does have his plusses. He's got primo wheels, he's only 28, he's an average BA guy and he might just be the best defensive CF alive (.903 RZR this season, .949 last year). Patterson might just have himself a prime, especially if someone sticks him in a bandbox. If his BA ticks up to .280-.290 range and his power settles in, then you might be looking at a discount version of Aaron Rowand.
Rocco Baldelli - B.J. Upton's going to be the D-Rays CF for the forseeable future. Delmon Young's in RF, Carl Crawford's in LF. That leaves Baldelli as a man without a place to play. He's beyond gimpy, but he could hit .300 with power, speed and a very good glove (though he won't be drawing many walks) if he could stay healthy. Tampa Bay needs middle IF and pitching help, perhaps LH power too (e.g. a guy like Jr. to DH). There'd be no point in trading Brandon Phillips for him (same basic guy), but he's a fairly established CF without a job.
Carlos Gomez - Carlos Beltran may be the best player alive. Then when you add in vets in the OF corners and two other primo OF prospects, the Mets are swimming in OF talent. Does that mean you could pry away Gomez? Don't know, but I'd ask.