I think the best way to explain a wahabi is like this:
They are pretty much a bunch of cunts with a literalistic interpretation of the Qur'an and the Hadith. They have this because they all claim that it is better to research Islamic texts that have been send down by Allaah and his prophets as opposed to what they call 'blindly following the madhab'. This mentality is actually I find a better way for learning about stuff, but it's the way these people act that makes me refer to them affectionately as a 'bunch of cunts'. They are wholly pedantic as they're more concerned about whether you put your hands together in the second time you stand up during salaah(I forgot all the arabic names for everything) rather than the moral/ethics of the Qur'an. They claim superiority over the other Sunnis who follow the imams of the Madhab even though those who follow Shafi'i are pretty much similar to them. Hanafis hate wahabis and vice versa because they follow contradicting Hadith with regards to salaah(though to be fair, the Hanafi method of praying is supported by Hadith collected by Abu Dawud and the Wahabi's methods are supported by Bukhari so they have the upper hand in this massive wankfest).
Generally, the Wahabis tend to be very arrogant about their beliefs as they believe that their research makes them as qualified as a scholar(which to be fair again, is somewhat valid as I'd rather study shit myself than get some cunt to indoctrinate me with his opinion). The problem with their approach however, is the arrogant tone that they take in discussions as if they're automatically correct. As someone said, a common saying of theirs is 'WHERE IS YOUR DALEEL BROTHER?!'. Another minor point is the sheer pomposity in referring to themselves as 'Salafis'(you have to take an islamic mindset here when you consider this pompous, as it just seems assholish from an outside perspective but the intention here IS to be pompous) as they are pretty much saying HEY WE ARE REMNANTS OF A PURE AGE AND YOU MOTHERFUCKERS IS CORRUPTED. That's just me going into ISLAM MODE though, as I gotta do that to remember anything about the damn religion :/
Another conventional opinion of the Wahabis is that everyone who follows anything different to them is automatically inferior in their imaan(or their faith) as they have failed to study for themselves the so-called infallible Qur'an and Hadith. They refer to the Shi'a as being kaafir, followers of the Madhab as sinners and Murtads(like us) as being DISGUSTING REJECTERS OF THE KALIMA WHO MUST BE CONSTANTLY CAUTERED FOREVER.
To be honest; I like the Wahabi approach to studying Islam. What I don't like is their assumption that what they are studying is automatically infallible because that's just intellectually dishonest.
I'm an Ex-Salafi/Wahabi btw

(note how I'm also being a pompous arse by saying MY WAY IS THE BEST WAY TO EXPLAIN THIS)