I use quicktime pro aac VBR *Unconstrained* 192kbps, which i was told is the best encoder there is..
however I saw a listening test before some guy said ogg vorbis is the best....is it?

There exists nothing as "absolute best". Only things appropiate, or better than others for a specific task.

Said that, for aac audio, and iTunes, using quicktime's unconstrained vbr mode at 192 is definitely a good setting. Is Vorbis? It's not clear. The tests that we did were done against iTunes' encoder (which is not the unconstrained one) and vorbis seemed to be partially above iTunes. Also note that this was done in 2005 and the encoders have improved.

Also, note that newer tests were done with Nero's AAC encoder, which produced better results on the average, so you probably should take a look at this one too.

In my testing, Vorbis is better IF you use aotuv's encoder (5.7+) lower bitrates encode FAR FASTER, and sound better enlarge, higher bitrates still encode faster and sound about the same, again main diff being that i can encoder FAR FAR faster with vorbis then with AAC, oh yeah and my audio players batts last longer with vorbis then with aac

both the aac and vorbis encoders have advanced, and they are both great for quility per bitrate.

If you want another option thats VERY VERY good and encodes/decodes fast try MusePack(mpc) I am activly trying to get musepack support added to the sansa fuze(sandisk seems willing to add codec support, they added ogg and flac already!!!)

Agree.
For lower bitrate (90-160 kbps) I would prefer vorbis, but for mentioned range (190-240 kbps) I use Musepack.
Why? Because they are free, open source and very, very good (as already mentioned).
Just my 2 cents.

Well technically it is the best if you are looking at it in terms of the technology and it being open source. In terms of sounding good well you really need to perform a series of ABX tests in order to determine that. If you are using Vorbis the general consensus in the community is that a -q 5 or better should be sufficient enough for your listening needs. You might want to consider AoTuV 5.7 as well. In terms of AAC. I would stick with Nero. I use Both Vorbis and AAC for different listening environments. I use a -q 8 with Vorbis and -q 0.65 with Nero. Again this is factoring the HD space I have, which is more then enough.

with aoTuV 5.7 you can get away with lower bitrates, 5-7 range for "always transparent", I find that anywhere from q0 to 3 is plenty for most music tho, This is especially true in portable audio environments, my fuze sounds excelent with 64-96k vorbis files, some tracks need a bit more or the BS version of aotuv encoder but thats pretty rare really.

You will also find that the aotuv 5.7/bs1 encoders are faster then the stock oggenc, manytimes close to the lancer enhanced vorbis (supports sse and multi threding)

quility is subjective and track based as well, take a listen and see what YOU YOURSELF THINK.