I'm an avid fan of mods, though. It's not hard to find a mod that makes your allies essential or removes their level cap or rearrange their skill setup.

Personally, I find the followers to be unnecessary, but they also add something to the game in my book. A much absent feeling of not being alone. Some settings are enhanced by desolate isolation, but Skyrim never felt like that for me. Besides there's not a great deal to differentiate your character normally (you're pretty much the omni-hero in any case), so it's your choice of companions/spouses that really add some much needed definition to the dovahkiin.

It should be said that compatibility is a fairly important thing, here. A thief/assassin/sniper wouldn't want to take Lydia along, as she's got no stealth. Aela, Cicero, Eola, and Faendal all have good amounts of sneak skill, with Aela and Cicero capping at level 50 and Eola and Faendal at 30. Not that it matters much to a mod-user. Brelyna, Marcurio, Adelaisa, and Ogol all have it as a minor focus as well, though they all cap at 30.