I have climbed 19 routes in the Dolomlites area. My favorites:
VF Bolver Lugli: Pale Group. Medium-hard difficulty. Long route to the summit of Cima delle Vezzana (3.192 m). Some of the best rocks I have come across in the Dolomites. Climbs the impressive North face of the Pale Group. Great variation - and you get to ride the cable car Down
VF Giavanni Lipella - Tofana di Rozes: A long route (8 hours) to the summit of Tofana di Rozes. Not so difficult, but the scenary is really amazing and you get to climb one of the major summits in the Dolomites. Starts out with 500 m of tunnel climbing and runs along breath-taking terasses!
Marmolada west grat: Another long route (6,5 hours). Again not so difficult, but great variation (you need crampons, rope and ice axe), superb views and you get the summit the Queen of the Dolomites
VF delle Trincee: Short route, not so difficult (besides the first 20 m), but walking through the WW1 tunnels is cool and you have great views of Marmolada.
Routes at lake Garda are shorter and not so difficult, but the view down to the lake is not bad.
Have fun - the area is truly excellent!!!