Yea Mass Effect 1 is great, especially for the story. You can play ME2 without playing ME1, but you may be a little lost as to whats going on.
I too would suggest playing Mass effect 1 first, however .....
EA now has a new DLC called "
Genesis ".
Its basically a interactive comic that lasts about 15 minutes, filling you in on the events of Mass Effect 1.
Through out the story you are given choices to make (which are the key events in ME1), and the story changes depending on your choice.
At the end, it creates a save game that can be imported to Mass Effect 2.
If this is your very first time playing a Mass effect game, I would at least get Mass Effect 2, and this Interactive Comic.
This way youll have a good understanding of the Mass Effect universe, and story line when you start off. Youll get more out of Mass Effect 2 this way.
Ideally, playing through the 1st one would be best IMHO.
There are many other very good games out there. It just depends on what king of games you enjoy.
For me, Mass Effect Series, Dragon Age Origins (the 1st one), and Fallout 3 would be my 3 main choices.
But Im a huge RPG fan.