best monitor speaker under $2000

What do you mean by monitor? Do you mean stand-mounted speakers?

Of course you should listen to lots of speakers. We all should.
But, if you can't and you want a suggestion (seems that's what your looking for) I suggest the Gershman V-1s. I use them in my living room with a Denon receiver and hear excellent tonal balance, very good soundstage and engaging music.
You will need good stands- Altlantis is what I use.
There is a pair for sale on Adgon at $550. Not a bad price.
If you go there, demand that the seller ship the speakers in separate, very well packed boxes. My speakers were dinged up because the seller shipped them in one box.
Good luck.

Ellis 1801
Salk HT-1

Seasons greetings fellow A'goner.B&W speakers are usually a pretty safe bet with Rotel electronics.You could start with something in the new 6 series & some decent Bi-Wire cables for less than $1000.00 new, or if so inclined invest in something REALLY good that you could grow into like the 705's which I see for sale here for around $1000.00 in gently loved condition(plus get some decent Bi-Wire cables BUT don't go crazy).Another option might be a pair of Vienna Acoustics Haydn Grands,ABSOLUTELY stunning fit & finish with a beautiful,organic sound that should mate well with the Rotel.Although EVERYONE is going to tell you they are 4 ohm speakers & a very tough load I have spoken with Sumiko & have been assured that although they are 4 ohm speakers they have a very gentle impeadance curve & are fairly efficient & should NOT be a problem for any decent amp(unless you listen VERY LOUD).1 more thing,take Rlwainwrights advice above & save some money for GOOD recordings.The more resolving your system gets the WORSE some cd's are going to sound,that is your going to here how they are actually mixed which can sometimes be really bad.Most important,have fun with the process & enjoy the music.

Having owned Rotel(amp/preamp) and B&W together, they are a good match initially, but over the long run I, personally, found the slightly lean nature of the Rotel preamp and the zippy high-end of B&W became fatiguing and etched. It was through this that I learned I am partial to soft dome tweeters over metal in lower end speaker.

My suggestion is the used Jean Marie Reynaud Trente($1,400) speakers here on Audiogon as long as hard rock/heavy metal/electronica is not your primary music of choice.

They are extremely easy to place for good sound, have fantastic soundstage and imaging, and really present a deeply rich sound. If anything, they might err slightly on the warm, forgiving, side. But, their performance improves as your system does up to a very, very, high level. Match them with a good tube integrated and forget about it!