sizzling OD/distortion? you might wanna try the sansamp XXL Bass edition, which can easily be had for under 100 bucks
The Digitech Bass Driver is pretty decent for that sort of thing.
In my search for a bass overdrive I tested many and owned a few pedals. The ones I owned:
Behringer bass overdrive BOD100: I actually owned this. But... don't! No good. I do like some behringer pedals, the TO800 guitar overdrive is actually pretty decent, but not this one.
Boss ODB-3: Nah! only does extreme sizzling distortion, but not a pleasant one (in my opinion, and in my hands). You CAN get a couple of useable sounds, but not a versatile pedal.
Digitech Bass Driver: It does the sound I liked from the ODB-3, plus many others. You can actually get some milder overdrive sounds as well as sizzling heavy stuff ala Nightwish. This is one pedal I kept, although I don't use it so much these days (I don't play in a metal band).
Digitech Bad Monkey: a guitar overdrive that works FANTASTIC on bass. Great for mild overdrive. Really nice.
Ibanez PH-7, Phat Head: This one doesn't have a blend control, but the sound is alright, keeps bass definition pretty well. 3 modes: clean, overdrive and distortion, plus an "attack" switch wich adds some high end grit. I love this one on "clean" plus the attack... it just sounds dirty, raspy, but keeps all the definition. Not high gain at all, but very "metal". The overdrive and distortion ones go from relatively mild gain to quite high fuzzy gain. Add "attack" to taste. This is a good metal medal too, but I wouldn't personally sue it as a main pedal, rather as a second "flavour".
MXR M80 Bass DI+: Great versatile pedal, initially I only used it as a level boost/preamp thingy, but the distortion channel gets you some pretty good sounds, from soft overdrive (although not as nice as the Bad Monkey) to heavy distortion. The trick is to blend it properly with the dry sound... that makes the different between "urgh" and "yeah!" sounds, in my opinion.
If I were going to have only one pedal, the MXR would be the one. In fact, it's the only one permanently in my chain of FX. Then, depending one what I play, I may add others. Typically the Bad Monkey for milder fat overdrive, or the Bass Driver for more metal situations. I still like the Ibanez, and I kept it becaue it's got a few great sounds... but it's very noisy, lots of hiss... so I would use another pedal if it can get me close to the sound I'm after, preferentially over the Ibanez.
