1) the vibrant and very compact old village, with numerous boutiques, shops, and outdoor cafes -- including one I went to that claims to be the 2nd oldest continuously running cafe in France, Cafe de la Table Ronde. According to the sign it's been running since the mid 1700s. The old village is sort of perfect for my taste because it is obviously bigger than a city center in a small mountain village, but clearly smaller than a big city like Paris or even Nice. I just loved it.
2) the modern, up-to-date business district. I'm have always like cities that effectively mix old and new. I love quaint villages that are 500 years old as much as the next guy, but I get bored enless there is evidence of today nearby. In Grenoble you can enjoy a coffee in the old town, walk 10 minutes along the river, cross under the train station and emerge in a 21st century business park that is --by modern business park standards -- quite attractive architecturally. In this area you find universities, business schools, high-tech industries, and the school where I was based for the oral exams.
3) mountains! The scenery around Grenoble is stunning. I took the cable car up to the old Bastille and just admired the view --- including one of Mont Blanc in the distance. From the top of the fort you really get a sense of the history of Grenoble because you can see its development by observing the rooftops: first the old village near the river, then the early 20th century expansion, then the evidence of the '68 Olympic Games, then the modern construction -- including a large IKEA near the outskirts of town. Beautiful.
I don't know where I will be placed next year, but I'd be perfectly happy to go back to Grenoble. It's not the most convenient town to get to from here (evidenced by my two trains and one bus trip home yesterday), but it was worth it this time around.