How is Dungeon Defenders and are the dlcs worth buying?

Humble Bundle you will get it + all DLC for less than $7 PLUS some more awesome games. Don't get it from store, it's not worth it's full price.
Replay value: few characters, fun with friends, lots of maps and achievements so there definitely is stuff to do.

It's a great game with lots of replayability. I suggest you get the collection in the humble bundle now. It's especially good in co op.

Get the game, it's fun! Played it for like 60+ hours without any DLC lawl

replayability? this game is a never ending grindfest. :D If you can handle that and do enjoy Tower defense style games, go get it you wont regret!

also Dungeon Defenders 2 seems to become quite a different game. f2p, moba orientated. Part one is just Co-op and some pvp(which no one ever really plays cause it sucks)

It's one of the best co-op games I've played. If you've got four friends and you can convince them to buy it or you can get four controllers and a wireless receiver then it's super fun. So basically if your Forever Alone don't buy it, if you have friends do.

After completing the game, just stop; it becomes a grind fest for nothing (same skinner box effect which hook people with world of warcraft and the etc)