If you know me at all, you won't be surprised to find out that this is one of the first things I Googled after we got the RV. What follows is a thoroughly non-scientific analysis of the pros and cons of each remotely portable method of coffee-making suitable enough for coffee snobs (like me), ranked.

Honorable Mentions:

Single-cup Keurig (or other single-cup brewer): convenient, fast, easy clean up, but expensive, mediocre coffee, and didn't want to rely on having electricity available in case of dry camping
Pour-over: cheap, easy, good coffee, doesn't require electricity, but requires filters, longer brew time, and some mess (piles of soggy filters full of wet coffee grounds become more inconvenient when you have a tiny kitchen and irregular access to outside trash bins)
French press: cheap, good coffee, doesn't require electricity, but moderate brew time and annoying to clean/makes a mess

#3: Stovetop Percolator

A percolator is one of these guys:

By Imm808 (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

The way they work is you put the coffee grounds up top and water below, stick the whole thing on the stove, and then the boiling water evaporates into the top bit, soaks into the coffee grounds, and then filters back down below. I was surprised to find that the vast majority of RVers online said they use a percolator for coffee (or they use instant coffee, but we won't dignify a discussion about instant coffee...). Percolators come in both stovetop and electric.

Pros:

Small and portable
No filters required
No electricity required
Cheap
Aesthetics (it's pretty adorable, isn't it?)

Cons:

Makes mediocre coffee
Even though there are no filters, you still have a bunch of loose, wet coffee grounds to dispose of, which could be difficult in a small kitchen. Can also get clogged, etc. Easy to make a mess.
Only works with really hot/boiling water, which makes bitter coffee
Moderately slow brewing time

#2: Cold Brew

Originally posted by Cory Doctorow on Flicr at https://www.flickr.com/photos/doctorow/15522501666

To make cold brew, all you need to do is mix coffee grounds with lukewarm water and let it sit for a while. Proportions and timing vary depending on how strong you like yours to be, but I usually go with a ratio of about one cup coffee to four cups water and let it sit on the counter overnight. You end up with a coffee concentrate that's stronger than a regular cup of drip coffee, and the coffee is less acidic and less bitter than coffee that's brewed hot (so heartburn sufferers, give cold brew a try!). Now that cold brew is becoming popular, you'll see more and more products like this around for brewing, but I usually just use a big lemonade pitcher like this.

I do love me some cold brew. I brew it fairly regularly at home in SF, and I usually drink it by adding cream and water and popping it in the microwave. Occasionally I'll put ice cubes and water or milk in it instead for some iced coffee.

Pros:

Can brew a bunch at once and keep in the fridge, so it's fast and convenient and no daily mess
Cheap
Easy to brew
Yummy

Cons:

While it's really easy to brew, if I want to make normal-sized batches of it, I'd have to lug around large plastic pitchers, which seems like a waste of space in a tiny RV kitchen, especially if I'm only using them every once in a while
Clean up is messy; no easy way to dispose of coffee grounds
I normally use the microwave to heat it up, which requires power. If there's no power, I'd have to reheat water on the stove, which, at that point, kind of defeats the purpose
And yes, it's becoming popular enough that it's easy to buy in stores now, but I'm putting that as a con because buying cold brew every week or two would add up quickly
While I love the taste of cold brew, if I drink it exclusively, I do miss the aroma and edge of a cup of hot brew after a while

And the winner is: AeroPress

Look at this space-age beauty:

This image was originally posted to Flickr by Ldiggity at http://www.flickr.com/photos/97311086@N00/296877647/ — This image was originally posted to Flickr by Ldiggity at http://www.flickr.com/photos/97311086@N00/296877647/

Instead of using using time or gravity like the other methods above, the Aeropress uses pressure, which means you end up with something closer to espresso than to American coffee. The gist of how to use it: put coffee grounds and boiling water into the bottom bit, stick the top bit into the bottom bit, and push. The pressure created in the tube forces the water through the coffee and the small filter at the bottom and suddenly, coffee!

Pros:

Really good coffee
Doesn't require electricity
Small, portable
Really easy to clean
Easy to use
Fast brew time
Cheap
Durable/don't have to worry about breaking it

Cons:

The force required to push the plunger thingie down isn't ideal for half-asleep, pre-coffee users
The amount of YouTube videos of people giving their own "recipes" for how to use the thing is overwhelming. I don't recommend it. (The inverted method? What?)

Why the Aeropress? Well, I immediately crossed off the list all brewing methods that required electricity, just in case. The percolator, while easy and portable, leaves too much mess relative to the mediocre coffee it produces. And cold brew, while I love it, also leaves a mess and would require too much storage space unless I brew small batches at a time (which would be annoying). Plus, if I can't use the microwave to heat it up, I'd just be heating up water anyway, in which case it's not really saving me much time or effort. I'll probably still make it sometimes for variety, or if I want easy access to cold coffee in a hot climate. Which leads me to the Aeropress:

Favorite of obsessive coffeeholics around the internet. Easy, portable, good coffee, no electricity required. And most of all, an excuse to buy myself one after wanting it for years.

I used it for the first time on our first morning of the Epic Eclipse Adventure. Sure enough, it was indeed easy, portable, and good. So I'm officially a happy camper. Er... RVer.

Bonus plug: I really love this travel mug. It's the only one I've ever used that doesn't spill. You can even stick it into your bag when you're on the go.

First time using the AeroPress. Never thought I'd be posting a picture on the internet of me wearing my retainers.