if i like skyrim will i like fallout 3?

Probably. It really is Elder Scrolls with guns. I mean there's a different perk system and fighting is of course really different, but they're otherwise very similar. I think the biggest difference (other than guns) is that where Skyrim had all that natural beauty and stuff, Fallout has dull gray post apocalyptic wastelands. It's intentional of course, but sometimes you just start to miss grass and trees. Kinda puts a damper on exploration. Maybe that's just me, I dunno.

It also came out closer to Oblivion than Skyrim, so keep in mind the graphics won't be quite as sharp.

But yeah, it's more or less the same open world structure where you run around and take quests/work on questlines. There's a main quest but you can mostly ignore it if you want to like in any Elder Scrolls game. I honestly haven't played New Vegas yet but from what I already know it's more or less the same deal.

If you like challenges try Skyrim again:

Set the game’s difficulty to Hard. And or,

[*] Play your warrior Dragonborn, without using any magic (except were absolutely necessary). No Enchanting. Can only use found/stolen/bought items of magic. May use Health potions, but not make any potions.

[*] Play as a Mage. Cannot use any armour. Can only use daggers and Magic.

[*] Play as a thief/assassin, May only wear Leather armour, may only use dagger, short sword, and bow. No shield, no magic, the same as the warrior.

[*] Play as a Paladin. May not do anything unethical, cruel, or illegal.

[*] Play as a Cleric: Any armour is ok, may only use Rally and Healing spells, weapon is either the Mace or Hammer.

These challenges should make for an interesting game.

One other thing you might do: If the Dragonborn dies, start over.

You can change the difficulty at any time while playing the game, even during a battle.

yes, then play fallout new vegas