"What kind of amp should I buy?"
I get asked this a lot. And I beg out of the question because of the complexity involved in answering it properly. I'm never asked "what kind of speakers should I buy?" As far as I'm concerned, this is more important than anything else!
It's fairly easy to put amps into the Basic Food Groups: Fender, Marshall, Vox, solid state. What's harder to do, with less experience, is to understand how different models of speakers affect that selection.
Those amps have certain characteristics that one can learn to hear, and guitarists in general tend to be aware of these characteristics. Speakers are a different story.
If a guitar player has spent their life as a person that has always used combo amps, they're accustomed to hearing "the amp" as a whole as including whatever speaker came with the cabinet. This would tend to be, going out on a limb, more Fender amp players because of the fact that it's fairly rare to encounter a Fender amp as a separate head. Even when that happens, the player is typically going to have it plugged into the accompanying cabinet the amp came with.
Marshall players are typically not combo users. As such there is always the question of what speakers is in one's cabinet, what does it sound like plugged into a buddy's cabinet, the oddball 1x12 with the speaker-in jack, the 2x12 that fits in the car instead of the 4x12, or maybe even what does the bass player's SVT 8x10 cabinet sound like with the Marshall going into it?
So one tends to hear hard rock/metal players talk about speakers fairly often. At some point all experienced players start evaluating their speaker preferences, including the Vox aficionado. I'm writing this to suggest that the reader - if you don't already know what speakers you like, their different characteristics - should educate yourself on the subject before you spend $$$$$ on gear that you are not evaluating properly. You may buy your Holy Grail favorite amp, only to discard it for something else because you're hearing it through the wrong speaker!
I'm not going to get into detail about the differences; you can Google that, and there are ample videos where you can HEAR the difference. Having said that, one should look up one's favorite players and note what speaker they prefer, and use that as a starting point.
Effectively speaking you need to learn about the following. Note that a speaker magnet makes a big difference - alnico versus ceramic versus neodymium, and their relative size. The cone and dustcap design matters as well.
Celestion (brand)
"Greenback" style
"Vintage" series
Alnico Blue and Silver
"Generic" Celestions (65,75, 80 watt, etc.)
Jensen
C12 series
P series (alnico)
EV (ElectroVoice)
EVM series
JBL
E and D 120 series
Note that the company Eminence makes effective clones of all of the above, as do a few other brands. You still want to think in terms of the above, though.
So first, note what your favorite players use (Google!). Then, rummage on YouTube across the bazillion demos and comparisons of the above speakers. Try to see if you can think of some common characteristics you hear: dark (less treble), bright, bass-heavy, thin. Do you hear the pick attack more with one speaker or the other? Does one sound more percussive? Does one sound "clearer", or "muddier"?
Not only should you know this before going out and buying amp after amp and hoping something magically works out, it also increases your listening experience to music: you're educating your sonic sensibilities to these differences. I can point out these things in a lesson, but unfortunately not "here" in writing. If you're motivated enough, this is one thing you can learn off of YouTube somewhat. It's not to say that playing through these speakers isn't it's own thing, because it is - as well as playing through these speakers at actual volume!
But you'll be much closer and have a better idea of what you like and don't like. It might save you $$$$$ as well...