2. Buy an amp that has a power scalling feature (Suhr Badge 18 or 65 amps Soho)
3. Buy a low wattage amp less then 20 w(Marshall SL5,JCM1,JMP1 etc... , Blackstar Ht-1,5, Blackstar Ht-5) or any amp that has a switch to reduce the wattage(Tubemeister 18)
Hands down a Tweed Gibson Falcon ('61 or '62). Best low watt amp ever made. Why you might ask? First off it has trem and reverb (both are spectacular!), it has GREAT distortion at 8-10, and has a great clean sound too. Also it has a monitor output that allows you to attache it, via the guitar input of another amp, and make that monitor amp become a clone of the Falcon. Danny Gatton played through Falcons and showed that trick to some friends of mine. It's a real crowd pleaser. I've done this at several jams with bad sounding amps. These amps are transformed into big falcons. It's like a giant pedal but better. You can get them for between $900 and $1500 (for a crazy clean one).
Second pick would be a black face or early silver face Princeton Reverb, the second best small amp.....
I had the chance to test the Marshall 1974x at the boston guitar bar (guitar center near Fenway) and I must said that with an attenuator, it may be the best amp that I ever listen too.
If you want a crunch sound, you really need to crank up the volume, but the clean sound is really awesome and the crunch, my god
I just picked up a 3 Monkeys Sock Monkey 10. It's a 10-12 watt el84 driven tone monster that I can't stop playing! It has 2 el84 power tubes and 3 12ax7 pre amp tubes. Comes stock with a celestion green back 10 inch speaker. 4 knobs. Pre amp volume, treble, bass, master volume. The pre amp volume has a pull knob to boost the volume. The eq is REALLY sensitive but takes no time to get your tone dialed in. Super harmonically rich, great British sound, and light to move around. Try one if you can before you make your decision. It's really a great amp!