panecott

Mdellar,
You didn't really say what you're interested in so it's hard to advise you. Both places offer beautiful scenery and good food. Both are popular with tourists, but I have never found Lake Como to be overrun, as 5Terre is.
The most popular towns on Lake Como are Bellagio and Varenna.
5T has the hiking trails and very picturesque little villages, with beaches. And it is jammed with tourists.
You can travel between the villages on foot, by local train or by boat (altho' if the sea is rough the boats don't stop at some towns). Personally, I think Portovenere, is the nicest town in the area, altho' it's not part of 5T.
Lake Como is one of the most beautiful places I've ever seen. You travel from village to village by frequent ferry service. There are several spots in/near Bellagio/Varenna with magnificent gardens, and I think the area is generally more tranquil than 5T. It's the type of place that everywhere you look you'll find something special. There are several restaurants serving great food.

I went to 5T once for 5 days and that was more than enough for me. I've been to Lake Como twice so far and don't think I'll ever get tired of it.

Jean

All the comparisons are interesting but only illustrate how personal preferences influence our travel experiences. No one can tell mdellar in which place he/she will have a more enjoyable time.

For what it's worth (perhaps nothing), I prefer Bellagio/Varenna first and Portofino rather than Cinque Terre.

mdellar

Wow. Thank you everyone for taking the time to respond. I would love to visit both places because they sound so great. Your input was very helpful. I think that CT fits the profile of this trip a little better because we are planning on packing lightly, and possibly participating in slightly more "rugged" activities. I guess we will have to save Lake Como for our next trip. Again, thank you so much for your responses!