Re: use pronounceable if you want to remember the password; random otherwise
Pronounceable passwords of the CorrectHorseBatteryStable variety have the benefit of being much easier to use if you don't have copy and paste available. Especially if the keyboard you are using makes it hard to access symbols, or even numbers. I can type several correctly-spelt English words quicker than I can type a sequence of random characters, even if the words have a greater total length. I type for a living, and most people type at least quick enough to send text messages.
It's wrong to say these passwords would be undermined if other people don't use symbols. Go read the XKCD again, and pay attention to the numbers. Each word adds 11 bits of entropy. That means it uses a dictionary of 2048 words. You get that much entropy regardless of what other people do, and regardless of whether you include spaces or capitals at word boundaries, and regardless of whether the attacker knows the dictionary. (It surprises me how many people cite the comic without understanding this point.) If you need more than 44 bits, use more words and/or pick them from a larger dictionary.
Which highlights another advantage of using correctly-spelt English words: you can calculate exactly how much entropy you have, and it doesn't depend on security by obscurity. All the schemes based on songs or substitutions or whatever, you really have no idea how secure they actually are. And because you know how much entropy, if you need to add a number or something to satisfy someone else's arbitrary password rules, you can just stick a 1 on the end. You won't make it less secure by doing so.
The main catch is that you need to pick your words from a dictionary with a genuine random method. Don't use the first words you think of, or the name of the first thing you see when you look out of the window, because you don't know how much entropy that gives you. Ideally use diceware or similar.