Well, pretty much all of the good options have been stated, but here are my thoughts.
5150/6505 - Can definitely get super tight with the right boost/pickups/cab. I still feel the amp has a slight sag to it when compared to the Butthole tight amps, i.e. anything fryette/vht
5150II/6505+ - Tighter than above, and the upper mid bump lends itself to more tightness as well.
EVH 5150 III - Crazy tight, Channel 3 does not need a boost whatsoever. Blue channel boosted is heaven IMO
Engl Powerball V1 - Insanely tight, did not need a boost with this one at all, and I'm a boost junky. Too hollow in the mids for me though
Rectifiers - The 2 Channel Triple Rec is the tightest I've owned, and I've owned a shitload. Can get pretty tight, but doesn't touch the ubertight/percussive amps
Peavey Ultra 60-120 - Very, very tight amps. Pretty clear as well, overall not as full as the 5150's but definitely tighter
Peavey Ultra Plus - Similar to above, but more options, can be dialed to sound massive, or super tight and grainy/dry. Great option
Peavey XXX - One of my fav's on the list. Insanely tight, and very clear for an amp in it's pricerange. Best option on a budget, IMO
Peavey JSX- Similar to the XXX, but seems a little more low mid focused and doesn't cut as well. Still, very tight.
VHT Pittbull - Any - Amps are ridiculously tight, clear, and dry, some of the best out there, period. Very unforgiving though. Sound good at low volumes
VHT Deliverance - Similar to above, slightly looser and more saturated, not a good sweep on the single master volume. Still tighter than a 5150/recto easily
Splawn Quickrod - Not mentioned here yet, but it rivals the Pittbull in tightness as well as dryness and articulation, another favorite of mine. Just sold my backup for $900
Splawn Nitro - Similar to the QR, but voiced more modern, more low mids and a lot more low end. Still a super tight amp.
Mesa Stiletto Stage II - Here's an amp that no one mentions, but I love. Extremely tight on the fluid drive setting. Mesa's take on Modded Marshall. Very bright amps
Ceriatone Chupacabra - Modded Marshall goodness. Stays damn tight unless you really push the resonance, but has a nice percussive low end none the less.
Honorable mentions:
Randall Diavlo/Thrasher/Satan 50 - All very tight, but were far too modern and characterless for me. But, that's not what you were asking
Laney Ironheart - Also a very tight amp. Good tone, but seemed to thin out a bit once the volume was pushed.
I can't think of any others off the top of my head