You want to know why you absoutely must see Calafate? Because in about 10 years time none of that will exist! Glaciers are receding all over the world and there's very few places where you can experience them so easily. Don't miss Calafate, it is an experience to remember. Be sure to take the 3 glaciers boat tour as well, which takes you up to the enormous glaciers north of Perito Moreno -- you go past icebergs etc, any time the ice falls there are minitsunamis etc. You can also get crampons and do guided walks on top of the icefields, there's a tonne of activities. I also went to El Chalten for a few days of hiking.
Bariloche is beautiful but it does feel like Tahoe or the Okanagan. If you're from the Northwest, this is something you can probably skip it if you're short on days. If you do go though, try and book the daytrips ahead of time -- they take you out into the fjords and they are very popular so sign up as soon as you can. There's a great bike route along the lake, which you can also pretty much do by bus. There's decent rafting as well.
Puerto Madryn, just check the season, if you're there past the season not a tonne to see.
Andesmar is good service, spring for first class if you've got the cash and you'll get a nice big lounge chair like in first class on an airplane. 18 hours to Bariloche.
Calafate, you need to fly to pretty much. There is a once or twice weekly service that does the Ruta 40 from Bariloche down there, although it's pretty expensive and they take their time -- you stay at estancias along the way so i'm sure it's a great experience, but if you're short on time, take a flight Bariloche - Calafate.
3 years ago I got a flight BA - Bariloche - Calafate - BA for US$300... I wonder what that costs now!! Probably at least twice that, not sure. If you fly to Argentina on LAN perhaps they have a package, although I don't think LAN does the Calafate route, but they do go to to either Punta Arenas or Puerto Natales, can't remember which one it is that is access to the Torres del Pan national park.
This is another trip option, you could go to Calafate and then Torres del Pan, and then there is a boat that takes you from Puerto Natales through the islands, and stops in Puerto Montt. I have not done this trip -- some people say it's spectacular, but others sy if the weather shuts in, then you're basically stuck with not much to do. Puerto Montt leaves you basically directly across from Bariloche, and then I think the bus can connect you back, and then a boat from the Chilean side to the Bariloche side of the lake. You'd have to do a bit of research, but this might be a nice alternative to doing the loop and getting to see both places. And then bus from Bariloche back to BA... if you're into a backpacking style of trip, this could be a great experience and you'd meet a tonne of travellers along the way.
Have fun!
One other note: I went to Calafate in the middle of summer -- on the boat I still needed a fleece, ski jacket, toque, and gloves -- the wind seems to run through direct from the Antartic -- when you're not moving it's about 20 degres celsius, but the wind is biting.
