We got this game because the other half likes trains and we enjoy playing games (both together and with friends), so this seemed like a good mix and different to our other games.
There are several different versions of this game, including the original Ticket to Ride (which is US based), but we chose this one as the map is of Europe and we read some reviews that said it is easier to learn, teach and play than the original. I don't know about the original, but this is certainly easy enough to learn.
The basic idea is that players draw tickets (say London to Frankfurt) and then you have to connect these two cites along pre-set routes on the board using small plastic trains and by playing coloured cards. You frequently have a choice of routes, and you don't get points for "directness", only for being able to get between the two locations on the ticket - If you choose to go via Moscow that's up to you. You also get points for longer steps, so Edinburgh to London is a longer step than Berlin to Essen, thus it costs more (in terms of cards and plastic trains), but you get more points. The more tickets you can satisfy, the more points you get, but there are penalties for tickets left in your hand that you can't use.
In terms of the game, it takes upto about an hour and a half, depending on number of players, how long people take to think and their strategy - we typically take about 45 mins for a two player game. There is a resonable amount of luck involved, but quite a bit of strategy and although the game plays well with any number of players, it is most chaotic with 3 or 5 players (due to a very clever little rule change). For a family board game, it is not cheap, but you do get quite a lot of quality bits for your money (including 45 plastic trains per player), and it's a well thought out game with a big board and lots of cards with a nice feel to them.
In summary, it's a good game that's not just for Christmas and has a lot replayability. If you like playing "modern Euro boardgames" (ie games, typically from Germany, with a little more to them than Monopoly and Cludo) or have a thing about trains, then this is definitely for you. However, if you haven't exerienced modern boardgames, there are other, cheaper options to try first (like Carcassonne, Settlers of Catan etc.), but this should be next on your list once you are addicted.
In our view, although it's not cheap, it's well worth the money!