Yes, you should.

Incredibly underrated and overlooked game.

I have decided im getting it

I can lists you the basics of what the DLC's are about without spoiling anything, hopefully.

Dead Money - You basically get abducted by an ELDERly man whom is also talked about in Old World Blues and by the Brotherhood of Steel. You go to the Sierra Madre which was a casino before the war that hadn't opened and you work with 4 other's to open it up and have to stop the man that brought you there.

Old World Blues - Again, you get abducted but this time it's by the mentat-addicted pre-war doctors that are basically TV's with brains and they want you to stop Mobius whom is also mentat-addicted but you don't have to kill him if you want. And you can reunited with your original brain, spine, and heart if you want.

Honest Hearts - You join up with a caravan company called "Happy Trails Caravan Company" into Zion to make contact with the New Canaanites but you happen to be in the middle between two warring tribes, the White Legs and the Dead Horses. You meet a once notorious Legion legate and a religios man and you can help either one to either evacuate the tribe from the region or kill all the White Legs. You can also get some unique apparel and unique weapons and a new type of ammo caliber.

Lonesome Road - This is probably the most difficult of the 4 DLC's. Basically, you go into an irradiated place called The Divide to either kill or convince Courier 4 (I believe that's his courier number) whom has a cool name. You have a new type of enemy called the Marked Men and before they became what they are, they used to either fight under the Twin-Headed Bear or for the Bull. You also meet up with a cool companion from the Mojave which is his counterpart. In the end, you have 4 major choices, bomb both the NCR and Legion, just the NCR, just the Legion, or try to stop the missiles from launching. But between you and me, I'd bomb both of NCR and Legion once you have attained Idolized status with both or whatever faction you so they don't kill you on sight. Lots of cool armors and weapons in this DLC and MRE's!

Gun Runner's Arsenal - This give's you more ammo types, unique versions of weapons, and new challenges. Though, the weapons are expensive ranging from around 8,000 caps to around 22,000 caps but that's not a problem (at least for me).

Courier's Stash - Honestly, one of my favorite DLC's for any game. This gives you an Armored Vault 13 Jumpsuit, Lightweight Metal Armor, Lightweight Leather Armor, and Tribal Raiding Armor all of which are exclusive to this DLC. Also some weapons with unique names exclusive to this DLC, medical supplies, weapon repair kits, a Vault 13 canteen (keep it), and a decent amount of ammo to start you off with. And the armor and weapons are in the best condition possible as well.

Hope this is what you where looking for to solve you question.

There are 4 story DLC:

Dead Money
Honest Hearts
Old World Blues
Lonesome Road

And 2 item DLC:
Gun Runners Arsenal - Adds a bunch of new weapons and more powerful versions of vanilla weapons for sale by the Gun Runners.
Couriers Stash - Adds a bunch of equipment that the player gets in the begining of the game. There are 4 different files for this, I suggest you only use one at a time or it'll just make getting caps in the begining easier. Personally, I don't use any of them.

I'd recommend not using any of them at all. They really don't make any sense in the context of the game's beginnings, and any one of them makes your character too powerful to start with IMO.

I probably will use all of them cos im like that
What do you mean by install? I have only had one GOYTE by. Bethesda and that was Oblivion and it all came on one disc, and pre installed, so how do install the dlc from a different disc?

It's easy, you just need to have about 2GB of space free on your hard drive.

The Ultimate Edition comes with the game disc and the add-on disc. Just put the add-on disc in, it'll bring up a menu. Select what you want to install and wait for it to finish. Then you're good to go! You can also start playing the game right away and insert the add-ons later if you want, they're not designed so you have to start a new game to play them or anything.

Do i need to use a internet connection to install it? Cos i have a really slow internet speed, about 55kb per second

Nope, though you do need a connection to download the title update, which is only small so shouldn't take long. All the Ultimate Edition stuff installs right from the disc.

Cool, thanks for answering