Don't you guys find it annoying being back at level 1 and having to go through the process of levelling up, dungeon crawling, getting mauled by Bears and Saber cats etc, all over again?
Heck no, that's the best part!
Now, I only have one character at a time - I play one until I'm "done" with it, before going on to a new one. Also, I tend to take breaks between characters.... need to spend some time on
other games, after all. (Also, I'm a big fan of mods. So, while I'm busy playing other games, I'll still start downloading and saving new mods that seem interesting. Next time I make a new character, I install a different set of mods to try out. Means that the game isn't quite the same.)
Beyond that, there's always the different playstyles - sneaky thief type; big burly warrior type; mage type; etc. And with perks, Skyrim's characters will be more different than Oblivion's.... even more reason to play multiple characters! (Plus, I'm not going to try to do "everything" on my first character. I've skipped the DB, Thieves, and Mages on this one. Went Imperial rather than Stormcloak. lv54 and 80+ hours, and I still haven't been to Morthal and Falkreath, so maybe I'll save those two for my second character as well. So many options!

)
-----
I play with one character. Honestly, I haven't found a game yet that would entice me to play through it more than once.
That's interesting. Even with games that don't have as many different options (like Final Fantasy-type JRPGs) I've done at least two plays when I had the time (which varies by decade). With more linear games, I'd play once focussing on the story; then play a second time with a guide, going for 100% completion and/or the "good" ending if it had one. Games with many options? I've got alt-itis - making new characters is more fun than grinding one forever.... I've made bunches of Diablo 2 characters, Titan Quest characters, WoW characters.....