One cannot think of a guitarist performing live, without thinking about their guitar to some extent. Visualizing Jimi Hendrix's 'Stratocaster' with a wall of amplifiers behind him, yes the much emulated and desired Marshall Stacks, which are quite expensive. Eric Clapton, in his early years, preferred Marshalls as well, though he did also prefer to play a Les Paul, or his legendary 'The Fool' SG, before he switched over to a Stratocaster as well. Speaking of 'The Fool's' current owner, Todd Rundgren, who prefers an old Fender Mustang, is known to like the crispness of Peavey amplifiers. I have owned several Peavey amplifiers, including a P.A. and must admit, they are really hard to beat for clarity of sound. I also owned a Marshall Stack 100 Watts at one time, and attribute much hearing loss from it. Honestly, I think the same classic sound, with less decibels can be achieved, through smaller amps.
Really you must ask yourself, in relation to the guitar you have, what kind of sound are you wishing to project? Will this be acoustic? Straight ahead Rock and Roll? Country? Blues? Heavy Metal?
What kind of budget are you on? If you are like me, I would rather start with a smaller amplifier to get a feel, for how I like the sound and how it sounds with the guitar.
SOLID STATE VS. TUBE AMPLIFIERS
There are many guitar purists who swear by tube amplifiers over solid state. They want that warm crunch or presence of vintage tube analog sound. The cost of a vintage amplifier is expensive. One can also emulate or simulate the sound of a tube amplifier, from effects pedals, such as Ibanez Tube Screamer, which is quite popular, for this purpose. Behringer and Peavey have smaller amps which sound fairly good, with trans-tube technology, in relation to the vintage Fenders, Vox, and Marshalls. But for our purposes, we shall focus on solid state amplifiers due to cost for the beginner, versatility, and the simple fact, that digitally the sound can be reproduced, to an extent, only a professional would notice.
Let us assume that you have $100 to spend on an amplifier at this time. Note, you can always add effects pedals. In addition, due to digital technology, you can also purchase pedals which will simulate all the classic and vintage amplifiers.
There are inexpensive practice amplifiers out there ranging from $30-80, but it would be safe to say, that the bedroom, backstage or den is the only context you will be able to use them in. Usually they are about 10 Watts of power, although good in tone, you may want to consider something that can be used in other atmospheres, such as jamming along with friends, or even having enough power for small clubs, or coffeehouses. Among those smaller amps for practice:
Rogue, Peavey Audition, Rocktron, Ibanez, Behringer V Tone, Kustom, Fender Frontman 15G
Behringer Ultracoustic, Pignose, even a 10 Watt Marshall
These amplifiers may be what you are seeking if you are considering to mic them through a P.A. System, or you really just want an amplifier, to jam along with songs in the comfort of your bedroom, but it is best to consider amps starting in the 15 watt range and going up from there.
By the way, don't feel embarrassed by the use of pedals and effects you will find that most guitarists use them.
Lastly, you may want to get a custom handmade amp built for you by someone like Jack at jacksaxe.com. Custom amps have the advantage of being built to your desires and needs.
Whatever you do, make sure that you have done your research before buying an amp. You will be glad you did.