Well, I have a Whirlwind passive direct box. I've owned it for at least a couple of decades. Don't have much to say about it either positive or negative. It does what it's supposed to do - match the impedance of your bass so you can jack in direct to a recording console. But it really doesn't do anything for your tone. In these situations, you basically find your tone through the use of EQ and compression. I've also used the Countryman DI on several occasions, and I'd have to say that I find it somewhat more "musical" than the Whirlwind, although the difference is subtle. I don't know if I would call either of them "the best" though. I do understand that Avalon makes a really, really nice one.
The SansAmp is really nice, but it's not actually a "DI" per se. It's a full featured bass preamp, which just happens to fit in a convenient stomp box. I would personally be MUCH more likely to record bass through something like this. I have the MIDI-capable, rackmount version, called the PSA-1. I also use the preamp output jack of any of my assorted bass amps for recording. This usually give much better results than a plain vanilla DI, as far as I'm concerned. In fact, I can't honestly remember the last time I recorded bass with a DI. I usually record direct from some sort of bass preamp. Either the SansAmp, or
my Boss GT6-B, or the pre from one of my bass heads.
Another good way to direct inject your bass signal into the recorder is to use a mic pre. The tube pres tend to sound pretty good on bass. In fact, I've heard people claim they got excellent results with the Presonus Tube MP, which is generally NOT well thought of as a mic pre. I've been very tempted toward getting a Groove Tubes Brick for this same purpose. At $400, it's reasonably priced for a quality direct box. You could consider it's uses as a mic pre to be a free bonus and, unlike the Presonus, it certainly IS considered a nice tube pre for a mic. For that matter, almost all of the quality mic pres out there these days have a 1/4" high impedance jack, and can be used with great results as a bass pre.
My point is, although people always talk about recording bass "direct" with a "direct box," much of the time that they are tracking bass, they are
actually using a preamp of some sort (either a bass pre or a mic pre), rather than a passive direct box. And this approach will generally yield better results, IMHO. As always, experiment as much as possible and find what works for you.
Brad