Paris City Pass vs Paris Museum Pass

The Paris Museum Pass is generally the way to go, just buy Metro tickets separately, a carnet of ten is around 14 euro or so. Passes other than the PMP tend to have all kinds of other "valuable stuff" like discount coupons thrown in that most people would not use, or not use enough of to make it worth it.
You need to be strategic with the Museum Pass, it runs for consecutive days, so don't "activate" it (on first use) until you have that figured out.

My experience echoes Dave's - my sister and I each bought a 6-day Museum Pass and a carnet of 10 tickets. How long will you be in Paris? We were there for 8 nights - one day we went to Versailles and didn't use carnet tickets, so the carnets lasted for 6 days. We bought a few individual tickets on our last full day in the city.

There is no such thing as a 'Paris Pass' or 'Paris City Pass' if by that you understand one card that allows transport, museums etc etc. These are commercial marketing schemes which take the normal museum pass and the overpriced tourist rip the 'Paris Visite' transport pass and combine them in an envelope perhaps adding other coupons or attractions.

For museums -- if you plan to visit many in a short time (typical on a first visit) then a Museum Pass is good value and also allows you to use special security lines some places like the Orsay or Orangerie that are shorter.

for Transport, the only pass that generally makes much financial sense is the Navigo Decouverte which runs weekly Mon-Sun --- if that isn't a good fit then just buying carnet of ordinary metro/bus tickets 10 for 14.10 is generally the best idea if you are fairly centrally located. On a day you go to Disney, a mobilis 5 zone day pass is probably a good idea.

Ignore all the attempts to sell you these same things for a lot more through various commercial packages which just add a fee to put them in one place.

I will echo what Jane says. Just get a Museum Pass for the number of (consecutive) days you need it and either get carnets of tickets (10 tickets in each) or check into a Navigo Decourvet (sp?) card which starts on a Monday and ends on a Sunday, if that fits your travel times. We used that and it worked great.

Good information from everyone, but can you remind me how the tickets in the carnet work? Is it time-based or ride-based? If I ride the bus from Point A to Metro Station B, then metro to Metro Station C and bus to Point D, is that one ticket or three?

Thanks!

As far as I know: Metro is one ticket for the entire journey -- transfers between lines (as long as you don't exit the system) are included. Bus is one ticket -- no transfers. So three tickets.

metro/bus tickets are good for one ride. you can transfer from bus to bus going in the same general direction to get to a destination; you cannot hop off, take pictures or shop, and then hop back on the same bus on the same ticket. tickets do not allow transfer from bus to metro or vice versa. you can transfer as many times as necessary within the metro to get to your destination but once you exit the system the ticket is 'done.' i.e. they are 'ride' not 'time based' tickets although there are time limits on each which are largely irrelevant since a trip is completed within the time frame. (if you got checked by an inspector and the ticket was for a much earlier metro ride, it would not be valid for examples)