Oh boy, have I got experience on this issue. Where to begin...
Boa's are one favorite. Pros: one of the easiest to put on and take off, stay on well even in muddy conditions, traction seems to be good, easy to care for and keep clean. Cons: expensive (but so are the others), caps have been known to come off so if you go with these buy extra caps, boots come up over the coronary band which in turn, can cause rubbing or bruising if not careful to not over-tighten boots, a bit clunky and sometimes horses trip while getting used to them.
Note: you will need to drill drainage holes in the Boas.
Regular Easy Boot not a particular favorite. They are cheaper but a pain to put on, sometimes need adjustments made to the boot, i.e. cutting the back portion down and removing inside grips. Don't stay on well even with vetwrap over the hoof. They're okay in a pinch or if just riding on rocky terrain or for a lesson but I wouldn't trust them in mud/water and such.
Epics another favorite. Pros: with proper fit, they stay on very well, no coronary band issues since the boot does not come in contact, these boots work well for all kinds of terrain and can stay on all day long, good traction, easy to care for. Cons: A pain to put on/off sometimes (certainly takes more time than the Boas), might need to replace gators if velcro gets really dirty.
EasyBoot Bares These have a good theory behind them but from what I understand they are very difficult to fit and put on. The Epics are just so much better/easier if you want the same performance.
Renegades I haven't tried these yet as they are fairly new on the market but if they come out with a larger size to fit my big guy I will definitely give these boots a try, they look very promising.
In my opinion, I wouldn't bother with the Old Macs or Cavello. The velco gets really nasty and eventually just won't stay closed unless you only plan on using them on dry land. They are very clunky too.
Hope this helps!