While the Matchless Spitfire is generally considered the King of Amps (Amp of Kings?), other varieties do have their merits. Notably, the Sovtek Mig 50 has been known to produce a pleasing squeal, while the Trace Elliot Velocette does a decent Matchless impersonation. Other noted brands include:

• Vox (but only pre 1970)
• Fender (ditto)
• Marshall (likewise)
• Gibson (I see a theme appearing here…)
• Mesa Boogie (sometimes)

Brands with which the discerning tone aficionado would do well to avoid association include:

• Line 6
• Korg
• Anything digital
• Anything solid-state that isn’t part of the Roland JC series

Other amps you should buy

• Fender Blackface Deluxe
• Fender Blackface Twin Reverb
• Original Vox AC30 Top Boost
• Dumble Overdrive Special
• Original Marshall JTM45
• Matchless DC-30

— Greg

• All of you should totally buy an Epiphone Valve Junior! For the price, you will be amazed. — Fraser

See Also: Brown/Bier Theorem of Tonal Quality