Neruda, be wary of ign's reviews. These are the same folks who found Sony Streetstyle headphones to be "high end"
I have never been a fan of Yamaha minisystems. First, their speakers (like the speakers on most minisystems) are pretty cheap. I'm actually a fan of buying a good pair of speakers separately for most minisystems, since the stock ones are usually so bad (which is why I'm impressed with the Denon and NAD minisystems -- they come with good third-party speakers). Second, I'm just not a fan of Yamaha receivers/amps. In my experience (I owned a Yamaha receiver, and have a couple friends with Yamaha systems, one component, one mini), Yamaha stuff has a very "warm" sound that can be quite non-fatiguing but lacks detail and space.
I should also give full disclosure -- I'm biased against minisystems
They generally sacrifice a lot of quality to keep the price down. As I mentioned above, the speakers are usually horrible, and the sources tend to be "lets see how much we can throw into this small enclosure." The only minisystems I've been pleased with, or heard good things about (from people I trust) are the the NAD system (which is my "2nd" system), the Denon D-M line, and the TEACs (in that order of quality). Oh, and Linn and Marantz make some, but they're a bit pricier
So for $300, I think the Denon is hard to beat, unless you scavenge for a used system. You could probably get an NAD 300-series amp, or a used low-end Rotel, and a used set of $300 speakers (PSB-level) for around $300-$350 together, and then hook up your CD player to it.