Tube amps that kick ass?

Here's another vote for the Cary 120S. It is totally kick-ass in my system (replaced the NuForce Ref 9V2 SE). In my view it sounds better from bottom to top and it's especially kick-ass in the BASS! That said, it is not as quiet electrically or mechanically as many other amps. But when the music starts, I surely don't notice as I'm mesmerized by its wonderful dynamic and musical presentation.

All depends on what speakers you're driving.

used Atma-Sphere MA-1 Mk 3(140wpc@8ohms) for ~$7k-$9k or for a little north of $10k used, if you can ever find them, Atma-Sphere MA-2 Mk II (220wpc@2/4/8ohms)

Audio Research Reference 300 MKII monoblocks used ~$10k

Wolcott Presence 220M (220wpc@4ohms) - famous for driving difficult large electrostatic speakers like Soundlabs really well.

used Bat VK-150SE monoblocks ~$9.5k

Wavac MD-805m used.

The big Manleys and VTLs are always good choices. However, one that flys under the radar is a pair of Canary Audio CA-160 monoblocks. These will give you all the tube goodness but can deliver the mail in respect to dynamics and bass control. They thrash my Piegas around like nobody's business.

Shakey

If you are looking with a budget of $10k, but preferably $5k or under, I'll chime in. I have a pair of VTL MB 450 Signatures from several years back. I like them very much and they boot excellent tuchus, even when done in triode mode with a measly 225 watts, they do very well (450 watts in tetrode of course). With the bigger models, you just get more fanny-kicking prowess. The older 450s should be available used for <$4k, which is a lot of LPs cheaper than the 750s.

Of course, several of the other choices will be OK depending on your speakers. In fact, what is necessary to kick sufficient tuchus will depend ENTIRELY on your speaker load.

As a case in point, someone mentions the Wavac 805s used. There happen to be a pair for sale. Cool! But note they are for sale because they don't meet the needs of the seller's current-hungry speakers. The Cary 120s may be a great amp - never heard it - but I have had a pair of speakers before where they would have been less preferable than the VTL 450s (OTOH, the Wavacs would probably do more than justice to my current speakers).

IF you have speakers with sensitivity in the 80s, and require current, and they have an input impedance dip down to a low 1-handle (like Martin Logan electrostats), then I have not seen many large tube amps which will meet that need other than big VTLs. If, on the other hand, the speakers are low-mid 90s dB with a more benign impedance curve, you could probably easily do OTLs with an autoformer.

A reasonably interesting thread on the subject came up last year and is here. Furthermore, the atma-sphere website has several white papers which make for interesting reading and may help inform your choice as regards tube amplifier topology.