Buy Carl Zeiss Jena 1Q bins multicoated, Dekarems, Jenoptem W, Binoctars (for ultmiate sharpness but small fields, Deltrintems and the 15x60s or 6x18s. Jenoptik 8x30 Waterproof are great, Dokter or Nobilem anything are terrific. Older D&D which became Meopta are terrific. Buy Bushnell Custom 7x26s. Buy Tasco 410 10x50s for a huge surprise of view. Buy Hensoldt IF 10x50 military Bundeswher and be stunned, or Fero D-12 or Fero D-16 8x30. Steiner 8x30, 7x35 and 7x50 Military are terrific. Zeiss Oberkochen 8x30B are fabulous. KOMZ porros are terrific, especially the 12x45 Navy, the 8x30 Baigish and the 5x30 roofers.
Any Korean era 7x50 IF Military bin from Spenser, Canada Leica, SARD or any B&L or Bushnell Zephyr is going to be terrific. The M19 military bin 7x50 from various USA manufacturers is excellent. All of the early Nikon E series or progenitors are super, especially the Gold Ring series or the Black pre-E single coat. All Mikrons are great (made by Nikon. The Tasco 8x30 IF Offshore is really nice especially if the price is low. My wife got hers for $45 delivered. We hate roofers here but the Discovery Channel Store 10x42 at $75 a pair are terrific. Redhaed 8x42 roofers at $50 a pair are also great. I even have a pair of Hensoldt 6x24s with nearly no eye relief that are super sharp and useful during the day and very lightweight.
Any Jason Statesman is going to be good (although I don't like zooms, theirs is "okay"). The 7x50W is outstanding. The Korvette 13 degree field of view 7x35 is a space walk and really nice but very heavy as the prisms are BK7 and huge. Stellar made a terrific 8x25 regular porro and a reverse porro (as did Hoya the galss company), all are excellent. I have a pair of Celestron 6.5x44 ED porros that are still wonderful as are the 8.5x44 ED Swift Audubon. Any Zeiss Oberkochen 7x50 Marine IF porro T8 is fabulous. I like all the Yukon Futuras (sadly discontinued) but especially the multicoated 7x50W and 12x50W.
The Russin Tento and Berkut 7x35 and 7x50 multicoated models are excellent. The KOMZ 10x42 IF is rated the sharpest binoc in the world even today (the color rendition isn't perfect, but whatever). The Zeiss 10x40 Dialyt is considered a great classic roofer.Any of the really good Kern or Swiss porro bins are good. Maybe the KOMZ 7x30 military bin is the 2nd sharpest bin ever but that is a question you need to check yourself. The name Carton and Adlerblick are great bin makers from before. The Takahashi 22x60 is no longer made but it was considered the best flourite bin ever. The Williams Flourite and ED porro bins were also fabulous, but no longer made. The Minox 6.5x32 aspherical IF is also super but discontinued. Go back to any of the older 10x70 IF Nikon Astroluxe or 7x50 IF Prostars and you will have one of the best bins ever.
The entire Fujinon line-up is filled with incredible bins. I have a pair of the first 6x30 FMTRs and they are superb (although the Meopta 6x30 Berlin wall models for Czechoslovakia are superb as well), and the Hensolt Algerian 6x30s are incredible with Neutral/Polarizer/and/Blue filters to add on for desert use, both made in the 50s. The old Steiner 9x40 Bisons(?) were CF, and waterproof. I see incredible deals on Carson XMs from the first series all the time. I have a pair of the Carson filtered 10x50s that are also very good. Tasco Marine 7x50 IF #3222 are also great.
Other reverse porros that are excellent include the 8x25 Steiner Champ MC, the Bushnell Birder 8x30 and the 10x30 Leupolds. I collect binoculars. I often have people offer older bins in trade on stuff I have NIB and when I look thru them I am shocked with WOW. There were allot of Dr Wohler, Heine Ranger, and other bins that are superb. If you ever see the Nikon 10x35 E bin, buy them. You will end up with a collection of bins dominated by superb porros, many in lightweight magnesium and usually razor sharp. Take an extra look at military bins since every one has likely been tested 5x, because lives depended on them. That also means that ANY Yellow body US Coast Guard/Navy bin in 7x50 or 6.5x45 (NATO) is incredible. Older Steiner 7x50 Marine IF and 10x50 Bayreuth are great as well. There are so many it is difficult to list them all from memory.