i wouldn't get it now..... black ops is the #1 and funnest game right now. you should get call of duty black ops. so no I would not get halo reach because it is boring now.
If you're one of the few gamers that actually appreciates a game's campaign anymore, I'd say give it a shot. I didn't get through the entire campaign in the time I had it rented, but from what I did play it was enjoyable.
I've never been a big fan of Halo multiplayer, so I wouldn't be able to give you a solid opinion on Reach's. I'd say rent it, and see for yourself.
Well it depends on what you want, a great campaign with some pretty good multiplayer, or do you want a game with average short campaign with amazing multiplayer and a co-op mode. Thats all your choice, try renting it and seeing for yourself