I have 2 different numbers.  Only 1 that counts officially for the straight pool purists and even though the other many wouldn't think anything of, it's probably my proudest achievement.  
For the one that counts, 46 on a 9' diamond with 4 1/2 inch pockets, fairly worn in cloth.  About 4 other runs from 40-44 on similar table.  I rarely play anywhere but home these days, but try to run balls sometimes, just for something different to do and I do like straight pool, even if I'm not on a 9' table.  
For the other run, I ran 100 exactly on my diamond bar box in my basement.  I've run 4 5-6 packs in various games, but I consider this my single greatest achievement.  I've run 62 twice, for my second highest as well.  
On the 100 ball run, I figure I made between 10-15 combos, billiards, and caroms.  In nearly 30 years of playing pool in general, I also made the single best shot of my life, around the 40-50 ball mark.  I was frozen to the top of the stack and after looking the rack over for a good couple minutes, I saw something that sort of resembled a shot that I didn't even think would go, but didn't see anything else that remotely resembled a shot.  I had to shoot a 2 rail kick up table, double out of the corner, hit a sliver of a ball, then have a ball 3 balls down carom off another ball, and then have that other ball go in the corner pocket.  I also had to hit this kick with pace.  Jacked up over the stack and on the verge of miscuing, I gave it my best stroke and to my surprise, hit the sliver exactly where I was hoping, and then after a collision of 4-5 balls, the intended ball found it's way to the pocket.  I couldn't believe I made it and after a minute or so of thinking I couldn't believe I just made that shot, I made a good decision.  I went to the bathroom washed my hands, stared at myself in the mirror and told myself I wasn't going to let that shot go to waste.  I composed myself, went back out and just kept stringing racks.  I initially started with a run of 1, then ran 7 racks, then made the break ball, missed the stack, and my run officially ended after I failed one of the trick shots I never make.  I had no idea where I was at and typically get to excited once I get in that 40 plus range.  I knew I ran what felt like a lot, but had no idea where I was at.  As I was adding up the numbers, I was thinking I probably ran 80-90, but not quite a 100, but thought maybe there's a chance.  When I saw it was 100, I was so damn happy and then added it up like 5 more times to make sure lol.  This was last year.  I'm only 37, have a Fargorate of 630, baby on the way, but think there's a good chance this will go down as my high run.  It's always possible I'll dedicate myself to the game more, buy a bigger house with room for a 9' down the road, but if it doesn't work out, I'm ok with that.  Also, not trying to start one of those debates about table sizes.  I'm well aware a 7' table is much easier than a 9' table for high runs, just something I'm personally proud of that I thought would be worth sharing.