I concur with the above post that the trick lies in matching the amp and the cab according to their voicing and construction/speakers respectively.
The 5150 has lots of biting upper-mids, often perceived as unpleasant spikes. If you want a warmer, less spikey and overall smoother and darker tone, you could consider an Orange cab. I had
the PPC 212 and it's a good combination. To prove my point: I realized I had to get another cab when I played my Diezel Einstein through the Orange. A dark amp through a dark cab is not an ideal combination, unless that's the tone you're going for. My other guitarist is now using his Valveking 100 with the Orange cab, and it's a good combination, since his previous cab was much brighter and more upfront. We didn't like the tone. The VK definitely has a brighter voicing than the Diezel and now its sound coming through the Orange is more balanced.
Other than that, I have played the Marshall 1960A. The T75s, albeit disliked by many, work well with the 5150. However, you have to turn up the volume more (and/or the mids), if you want to cut in the band. My other guitarist's 2x12 with V30 blew me away at that time.
I also had the Peavey 4x12. Naturally, it works with the head. But it's an acquired taste, so to speak. At first, I quite liked the sound but then I grew out of it. Too flat and two-dimensional sounding, in my opinion. But the Sheffield 1200s certainly go into a similar vein as the T75s. I ran other heads (i.e. the Savage 120 ) with this cab and they sounded shitty.