Tube amps
Tubes aren't cheap, and need to be replaced from time to time. They also need to warm up to sound good. Tube amps can be heavy as hell. The tubes can be fragile. If yoiu do get a tube amp, don't move it around while it's plugged in (or do so caredully), the tubes can arc and go monophonic. Don't ask me whyat that means, but you end up hearing a slight ringing sound sometimes. Most of the older tube amps only get that high gain sound when they are CRANKED.
Solidstate Amps
...are lighter, less fuss, produce more consistent sounds at different volumes etc...and are cheaper to buy and maintain (or used to be).
If it's all about overdrive, tubes are the only way to go, but SS amps are getting better.
There are many hybred SS/Tube amps as well, or tube amps with SS clipping circuits (like a D pedal) built in for extra gain.
A lot of common pop rock sounds are old Marshall JCM800 single channel amps with some kind of distortion pedal in front of them, but you won't find one of these cheap, and they like being turned up loud.
If you find "the tube amp" that does what you want it to, you probably won't regret buying it. A cheaper SS amp that makes all the sounds you need may have a long and usefull life span, and the money saved can be spent on the ultimate tube amp at a later date.
Doug