Welcome aboard. E39s are great, and everyone who has a E46 will say the same. Make sure you do some solid research about the common problems of the respective model you decide on and see if all the problems have already been resolved. Repairing a BMW isn't the cheapest thing to do. If you can I would get one that is still under warranty just for added security. Great luck on finding the right car for you, I remember my first BMW, you will love it for ever.