Re: In your opinion the best tube amp tonally that you can get nowadays
IMO, speaking only of brand new amps, I'd say the Fender Deluxe Reverb Reissue, the Ampeg GVT-52, and the Mesa Express Plus 5:25. Context is everything, of course. I am primarily an r&b-based rhythm/parts player, and not a lead player, though I do play your basic blues and surf leads and melodies if called for. Think something along the lines of Steve Cropper's approach to the guitar. I pretty much play folk, blues, r&b, country, early rock-n-roll, surf/instrumental, '60's pop, garage, hard rock, and classic metal.
The Fender is a basic classic sounding amp without a lot of "modern" features. Great amp clean or crunchy, and it can get nice and "smooth bassy" in that lovely way that low-watt Fender amps do. Although simple, it is extremely versatile if you play to get the most out of it.
The Ampeg gives a variety of tones, and some modern features, but basically it sounds pretty classic V series. It has a very bluesy thump and chewiness, and it's warm, yet aggressive. It's a very dynamic sound. It has a very distinct voice and character, which I love, but which might not be everyone's cup of tea, especially lead players. Again, very bluesy and hard rocky.
The Mesa has a very good basic "old school" tone, plus a variety of useful "modern" features, such as outstanding tone controls, two channels (with two gain settings on each channel), footswitchable graphic E.Q., flat-E.Q. boost, three power/mode settings, and several other fancy Mesa features. It's a stone's throw from being over-engineered, but they keep it from going over that line, like some of the Mesa amps do (e.g. the various Marks and Rectos). It's also built like a brick outhouse, like any Mesa. It's the perfect amp for someone who likes classic tones, but wants some modern style versatility and the utmost in reliability for gigging.
Of these three, the only one I would actually buy new would be the Mesa...and I did get one. With the other two, I am already covered by my Princeton, V-4, Jet, Reverberocket, and Super Rocket. But speaking only of brand new amps, and approaching the situation as if I didn't have any amps already, these would be the three I'd be looking at. If I was primarily a gigger, and played a variety of music with different people, I'd go for the Mesa. While it doesn't really have a "signature sound," it's a great grab-n-go, do-everything-and-do-it-well amp that will likely never leave me high and dry. If I didn't need as much versatility or reliability, and I wanted a more distinct sound, I would go for one of the other two. The Ampeg if I wanted a more syrupy and chunky sound, and the Fender if I wanted a more focused and biting sound.