Have you considered the official site?

http://www.firenzemusei.it/

I have always used:

http://www.ticketitaly.com/

and had no problems with them

I used www.tickitaly.com a month ago and no problems at all. I did try calling first and was left on hold. Then I tried the official website(firenzemusei.com) and my request wouldn't go through. It's not a very well designed website.
I paid the upcharge on tickitaly and ws happy to have it done!
BTW - I only bought the Uffizi - at Academia, we just walked right up. This was in mid-May.

www.firenzemusei.it *is* B-ticket. I haven't looked at the others, but I suspect they have higher mark-ups. B-ticket has occasional hiccups, but most of the time it works.

I don't quite understand your reluctance to phone. It doesn't take long, you have a wider choice of times, and you only pay when you pick the tickets up.

Calling is really easy. Remember the time difference from wherever you are to Italy, and that the booking office is open M-F 830-1830 and Sat 830-1230 (I think that is still correct.) From the U.S., dial 011-39-055-294883. A machine answers and speaks Italian to you, followed by English that directs you which buttons to push for museums you want to reserve. An English speaking operator comes on, you give the museum name, number of people, date and time you wish, are given a reservation number to present at the ticket office and Voila! you are reserved. And it is well worth it (free actually.) I remember the long line for those without a reservation outside the Accademia. We walked up, gave the reservation number, paid and entered - no line at all. Hope that helps!

I agree with everything castlevisitor says. It is a very simple phone call. I called last year about this time for September reservations and the phone was answered immediately by a lovely woman who spoke beautiful English and completed the transaction in a couple of minutes.

>>>I have considered using: Virtualuffizi,Tickitaly,B-ticket and Weekendafirenze<<<

Of this list, B-ticket is the official booking link.

With B-ticket, you will pay 14€ (6.50 admission + 3.50 exhibition fee + 4€ reservation fee). The price will be the same by calling.
http://www.b-ticket.com/b-ticket/uffizi/venue.aspx

Most of the other booking sites seem to be overcharging by about 7€ per ticket. That can mount up depending on how many are in your group.

With Tickitaly, you will pay 21€ for the same ticket.

Weekendafirenze charges 20.99€.

Virtualuffizi charges 20.20€

Walk-up price is 10€, but then you would have to wait in line.

We had no trouble using the phone either, but it was quite amusing when every so often during the process I was addressed in italian, even though I was talking to the english service.

I'd like to think that now, having been learning italian for a few years, i wouldn't worry about that, but if it happens to you, just ask them to speak english!

You might also consider the new Florence card or Friends of Uffizi card which will get you unlimited access to most of the sites (not Duomo) for about 50 euro a person.

when I was planning my 2 days stay in florence, i considered the firenze card, but i felt that €50 even for 3 days was a bit steep.

if you were going to be there for 3 full days and wanted to do the main museums and nothing else, it might just be worth it.

You may be cheaper to become a friend if you are under 26.
http://www.amicidegliuffizi.it/become_a_member.aspx

I'm guessing with the username mama_c, this person will be paying full price.

The official site is simple, reliable and I believe the least expensive. Easy to use.

I looked at the official site today for dates in October. Earliest time they offer is noon. If I call will they ave earlier times available?

gh - I've seen this before. I think there may be a glitch on the website.

no harm in phoning- if they only have time slots after noon, you've not lost anything,

however it's a good idea to know what times you are heading for, if you have a choice.

gh21-I followed castlevisitors advise and directions and used the phone-EASY. I did try the first time around 2:30 their time and it wouldn't go past the first prompt. Tried 2 hrs later and went through right away. I picked whatever time I wanted at both museums and was done in less then 2 mins. Us Cellular charges .50/min.
Thanks to all

brava, mama_c!

There are some useful tips on the two Florence museum passes here: http://tuscany-toscana.blogspot.com/2011/01/florence-museum-cards-florence-museum.html