Oh, and I forgot to mention hay... most folks buy it by the bale because it's SO much cheaper than the pet store stuff (and fresher, too). I actually buy it in bulk online, which is much pricier than feed store bales but still a lot cheaper than pet store hay (I'd rather get the feed store stuff but my girls are *really* picky and won't eat it). I've had two 20 lb boxes of hay stored in a very small bathroom before and the smell wasn't even noticeable; there's probably 80+ lbs in my living room now and it doesn't make the room smell like hay. It's all enclosed, but not in anything air tight.
When you actually open whatever box or bale bag you've got a ton of hay crammed into and rip off a handful to feed it to the bunnies, the smell is *very* strong; however, it dissipates quickly. Hay will still smell once you put it out, but you have to get pretty close to it (a couple feet or so) to really notice - it's only overpowering when you're first ripping it off the bale and quickly fades to a soft, hard-to-notice background smell.
You can have a pair of bunnies and maybe even a bale of hay in a small bedroom without it smelling like a barn - just pick a litter box substrate that's good at odor control, clean the litter box regularly and keep the hay in bale bags, plastic storage tubs or unscented trash bags + cardboard boxes so that the smell is mostly contained and the only bunny-related smell you should notice (if you notice anything at all) is perhaps a faint "meadow-y" smell. Some people actually buy air fresheners that are "meadow fresh" scent or whatever, so there's something to be said for getting the smell for free
My bunnies create far more messes than any cat I've ever had but in the year and a half I've had them, they've only ever smelled up a room the way a cat box tends to ONCE (and that was a rare exception). I attempted to free-range them a month or so after moving in with my boyfriend and his cats. Jay and I happened to have sinus infections that week and as we started to regain our senses of smell, we discovered that the "litter box trained" bunnies had made a full-time job out of peeing on
everything in the living room that belonged to the cats or was supposed to be shared between the bunnies and the cats (beds, mats, furniture, etc.). Nala and Gaz are far naughtier than your typical bunnies, though - most bunns don't get *that* spitefully territorial towards cats!
Bottom line is that if the room your bunn(s) are in smells like "bunnies" (ie rabbit pee) and/or a barn, that's not "normal" and
can be remedied (as opposed to something you just have to learn to live with, like occasionally finding hay in your underwear).
Oh, and as for the actual bunnies... mine sometimes have a very faint "bunny" smell; it's hard to describe, but it's a vaguely sweet, "clean" smell with a hint of fresh hay... like they've been frolicking in a pretty meadow. They kinda smell like they've just been bathed and blow-dried, lol, which of course they haven't. What I'm getting at is that it's a pleasant smell that you only smell when you press your nose against them (and even then it's very faint).
If your bunny itself smells of anything unpleasant, that's always indicative of a problem. The most common causes are standing in a soiled litter box (especially if you don't use a grid and have a litter where the pee stays up at the top), having a urinary tract issue that causes them to pee on themselves (which can lead to urine burn and needs to be addressed ASAP), needing their anal glands cleaned and failing to eat all of their cecotropes, then sitting on them and squishing them into their fur.
