The better examples of each type sound more alike than they do different. Tube amplification is addictive and can be expensive, but it is also alot of fun.
If you want to come home, flip on the stereo, and kick back right away, tubes may not be your best choice as these need time to warm up (30 seconds to 1 minute) and then time to really staibilize and sound their best. This can take 20 minutes or several hours, depending on the amplifier and the tubes in use.
Actually, headphone listening is an ideal way to get into tube audio, because the low power demands of most headphones minimize many of the less desireable tube amplifier shortcomings including: size, weight, cost, heat output, audio power limitations of many tube amplifier designs.
There is a great deal of information and listener opinions here in the forum on different types of tube and solid state amplifiers to consider. Ultimately, you may decide to own one or several examples of each type, as some headphones work especially well with a given amp, but not others.