My favorite are:

www.allhome.eu for Italy
www.wotif.com for world

www.accorhotels.com and looking for ETAP hotels that are centrally located or near a rail station.

have got nice modern rooms in Berlin for 30-35 euros; Paris the same and many other cities.

www.tripadvisor.com

Actually, I often stay in Accor hotels, also, in fact, I'm going to Monterey/San Francisco next week and am staying in a Sofitel on the peninsula.

I really don't ever look in one place for a hotel anywhere in the world, I have favorites by country.

depends on where I am traveling. I like Accor hotels and they are reasonably priced except for most Sofitels. I check many of the discount sites to see what is being offered in the area I want to stay, then I read the reviews on tripadvisor to make sure I will be satisfied with my choice.

For cities like Paris, London and Berlin I generally use Priceline and book a 4 star in a particular area. I have never been disappointed for the price I am paying.

I like to 'shop' with
www.venere.com
www.worldby.com
www.booking.com
because they have photos and reviews...

also use Google and Google maps, and Tripadvisor for reviews and candid photos.

I nearly always book thru the hotel's website.

I have seen lots of good deals from www.hotelscombined.com - because this looks at sites like Booking.com, Venere.com, Hotels.com, OctopusTravel.com, etc. all in one go.

But for one site at a time, I have had very good deals from these sites:
Booking.com
OctopusTravel.com
Accorhotels.com
HotelClub.com
HRS.de

Of course, bidding on Priceline has produced some very good results too.

My first check is always the website of the local tourist office because these guys know and list all the little private owned places which the big websites don't have.

(Do I have to stress that I disike chain hotels?)

Has anyone had any experience with bookinhotels.com?

I often find really nice places through VRBO.com.

tripadvisor.com I always check the reader reviews on there, no matter how I decide to book.
I never stay and big chain hotels if I can possibly help it, why go to Europe to stay in a Marriott or Hilton??
I also check reviews on Venere, but I almost always actually book the hotels directly through their own websites.

www.tripadvisor.com for reviews and then I email direct to each hotel or b&b.
For France I found a website gites-de-france
http://www.gites-de-france.com/gites/uk/bed_breakfasts

We found very nice b&bs in France on this website. I emailed directly to the b&bs. A few of them had never had Americans stay with them before. We really enjoyed our stay in France. It was a little challenging to find some of the b&bs in rural areas but we did it and we learned more about France and enjoyed to people we stayed with.

Hi!
There are so many options, I don't like to travel and stay in busy hotels. I got my informations, special to new touristic destinations in this site
www.whl.travel
It is totaly different of others.

I also like tripadvisor - the reviews are always helpful. I also recently found a new site called Tripfilms which allows you to view high-quality videos on a range of travel subjects and destinations...they have some very helpful "Where to Stay" videos. It's nice to see actual footage of places before you go!

http://www.tripfilms.com/search.do

I'm very partial to worldby.com and its ancillary websites, also to bookings.com. I like the many pictures both of these have. After I've sorted through and picked several good looking places in the area I want to stay, then I go check them out on Tripadvisor.com Has usually worked well.

I check several sites - venere.com, kayak.com and booking.com for ideas, then check out possibilities on tripadvisor.com.

for my upcoming trip I booked either through the hotel itself or booking.com.

www.tripadvisor

You can't go wrong with this website!

Good luck!

For our upcoming cruise we are staying in London for a few days then Copenhagen prior to boarding and Athens after the cruise. I used Skoosh (and booked one of their "secret" hotels - it was easy to figure out in their reviews) Got Flemings Mayfair for $189 for four nights. In Copenhagen I used Priceline because I was sure it would be the Marriott and it was for $125 and GTA for Athens and got the Amazon Hotel for $135. Oh, and for the one night back in London I booked Jurys at the airport through their website. I love tripadvisor for checking out the hotels but booking through their site has always been more than the others.

www.summerinitaly.com the best in Italy, followed by www6.cuendet.com
www.interhome.com for the world

www.traveleurope.it
There are a lot of hotels in Italy, you book on line but pay at the hotel, can read guests reviews and view hotels photos, and often there are hotels at discounted prices...