Best Budget Bookshelf Speakers?

I chose Aegis Ones for a small home office system after listening to most of the others you mention. Nice and smooth with enough detail to hold my interest. A little rolled off on top. The Stereophile review was accurate, imo.

But, all of these speakers have their own character. You might prefer one of the others. In this price range, you should try to hear (and look and touch - some differences in fit and finish) before buying.

I would try the B&W 303. They have tweeter technology handed down from their Nautilus line and the highs are reputed to be very clean. I personally feel that they equal or surpass the 601S2 at a 50% lower cost. BTW, outstanding build quality and fit 'n finish by B&W for their entry level speaker.

My favorite, for the price, have been the Kef Q15.2 . I have
used these in small and large rooms, and they are excellent.
I do have a pair that I was thinking about listing(just
got some Magnepans) for sale...but if I do or don't isn't
the point..you should give these a listen if you can.

The Aegis One is very good for nearfield listening. I have considered it for my home office as well. However, if you plan to set up these speakers at any realistic distance away from the listener (say 5 feet or more), I don't think these are the best choice. Of the ones you've mentioned I've listened to the Tannoys and the B&Ws. I have listened to other speakers by PSB, and have to say I don't care for them very much (obviously when talking about speakers it's very much personal preference). I would favor the B&Ws overall.