Borderlands 2, short lived fun?

So when i got the first Borderlands it was amazing and i played it constant nonstop, i loved it! But, now Borderlands 2 has came out, with all the extra things i would have thought i'd love it even more, but i'm just not finding the game as fun anymore at all! Anyone else found this with Borderlands 2, or any games' sequels?

Give it a go in co-op. Perhaps you'll like it better.

If you do the side missions and explore the areas,you can easily get over 50 hours out of the first playthrough.

This game is much better in co-op. Some of the side missions are a lot of fun too