There are so many different brands and options out there and opinions are going to vary greatly.  My advice would be to find a store to listen to different options if you can.  Read some reviews, compare pricing, look at the freq range they cover (particularly if you aren’t going to use a sub) and see what makes sense for you.  I personally like the JBL brand speakers, but I only buy outdoor passive speakers (no built in amp) these days, and certainly can’t say that I’ve extensively compared them to other options out there.

Also consider that Sonos One SLs as an option.  I think the audio is probably pretty close to what you would get out a pair of passive speakers, so you wouldn’t have to mess with speaker wire (just electrical cord) if that makes more sense to you.  

How do your DENON speakers sound? How would you improve them if you could?

Overall, a speaker’s power rating is not a meaningful comparison spec -- unless it is very low (indicating an inferior product). Since there is no widely accepted testing standard used to assign the power rating, cheap, lower quality speakers tend to have a higher power rating assigned by their marketing department -- higher is better, right?

That is all making sense.  It is about taste in the end.

The Denon speakers are good. Sometimes find vinyl sounds a little bright but then often they is meant to sound that way.  Especially older records.

Good point about the sub,  I do like bass but I don’t necessarily need a speaker with lots of it built in.

Likely need something with wife-approval.

Will take a look at JBLs.  I have a small movie room so watch a lot of surround sound videos and those feature prominently.  

Little has changed in passive speaker tech in many decades, so if they sound good, new ones are unlikely to yield a marked improvement in sound quality unless you make a good selection at a significantly higher price point - and that is best done by actual listening as opposed to advice on a make here.

But if you want to change just from the looks, there are many options from the likes of Dali, KEF and the like. Speaker box size - up to a point - still remains a factor so don’t go much smaller than what you have.

Although it makes comparisons difficult - or perhaps impossible - I have bought nearly all my conventional hifi equipment newish second hand or ex-demo.  This has enabled me get significantly better gear for a given budget.

And if you don't like the speakers you can recoup most or all of your money by selling them on.

My PMC floorstanders were about £1800 new when I bought them second hand for £900 about 12 years ago. They sound as good as they ever did to my ears.

It isn't for everyone, but I mention it just in case.

Excellent point; if one can access this market easily, this is the best way to value for money in home audio. The supply is taken care of by audiophiles that are driven to upgrade with a majority of service life still left in the kit, for no reason except to make a change. Ironically, one of the selling point for the kit they sell in a short time is that it is built to a very high standard and consequent high service life to justify the high price paid, much of which has little to do with sound quality as such.

Frankly, a large portion of my Sonos equipment, perhaps beyond 50%, is open box stuff from Best Buy. I assume from people who couldn’t understand a network was required for a networked sound system. I’ve yet to have an issue with any of them. Slightly off topic, I’ll grant you, but does reinforce the point that ‘new in box’ is not the only way to purchase acceptable equipment. 

Good advice on the second hand.  I happened to see some Kefs that are normally over a grand and there is an older model as well as that on eBay for just over half.  They are tempting based on aesthetics as well as reviews but I haven’t heard them myself.

I’m in no mad rush.  Just preparing the groundwork.

As mentioned it is tricky because tech hasn’t really changed much and Wattage isn’t really much of a guide.  I can absolutely keep the old speakers, chips, scratches and all so it is purely about the luxury of thinking about something new.

I might have a trip to my nearest city, Edinburgh, soon and they have a couple of good shops where I could have a listen.

Also, given that you now have a much more powerful amp, it may be worthwhile seeing what is there on the speaker side of things to put that extra grunt to use on occasions.