Site specialising in products - principally decals - to put off wild birds from killing or injuring themselves by flying into windows.
Easy-to-fix decals (static cling only, no adhesives) that reflect UV light and so are highly visible to birds. To human eyes they look like quite attractive etching on the window. UV reflectivity wears/washes off after a while (4 to 6 months?) so it pays to check them, either with a UV flashlight (they sell one for a few dollars) or, with experience, just by looking.
Efficient ordering and reasonably priced shipping, now with tracking.

Expert, fast and friendly site for specialist covers and bags - particularly for musical instruments and amps but also for removals.

Excellent site for supplements.

Loses one star because, for shipping outside the UK they insist on extra payment for "signed for" delivery (although here in France that is rarely followed up - the package just ends up in the mailbox as usual). This charge can make a smallish order much more expensive.

If only I had found this site before being ripped off by m*siciens-dans-t*-v*lle.com.
Good forums and contacts with other musos.

Voyez les commentaires (en anglais) sur le site souer musicians-in-your-city.co.uk

Excellent site - and if you place enough orders to make it worthwhile subscribing to Premium (about 40 Euro a year, with other benefits including Kindle book rental), next day delivery for no extra charge.
Almost embarrassing when the UPS guy arrives with next-day service on an urgent package - containing an item costing less than 10 Euro.

(this concerns the French version of the site - musiciens-dans-ta-ville.com - apparently they have threatened serious legal action against anyone trying to defame it in France - now why would they need to do that?) Getting bored with musicians who "would like to contact me" but - as neither of us were paying members - it was impossible to get in touch, I stupidly paid for a year's membership at 59 Euro.

I tried to contact one person (who has previously expressed interest) - when there was no reply after a week, I opted to cancel my membership.

They refunded FIVE Euro, referring me to a ripoff scale of charges to be deducted for "services used", including 20 Euro per pass contact (my 59 Euro annual subscription included 30 of these!),

An absolute ripoff.

Right now I have asked if I can pay them back the 5 Euro to restore my annual membership (it isn't worth a lot more than that though). Watch this space.