It's generally just an indicator of a failure to find a boot volume - sometimes something as simple as setting the Startup Volume in System Preferences (I just noticed something 'funny' about mine but can't share it just now).
I'm hoping - for you - that it's as something as simple as a cable. I've installed so many hard drives in Macs over the last 27 years and never had a problem (fingers-crossed). I find it strange that you're having so many problems with so many drives...
Let us know what works,
That may be because of running the drive over USB. Here's the thing: When you clone a drive, the possibility of data corruption increases exponentially because of the sheer amount of items being copied. And the replacement drive you purchased may not have been playing well with your Mac to begin with, which could be where the trouble began.
You might want to properly reinstall your original Mac hard drive, zero it out 1x to clean it, then use recovery to get a clean, pristine OS running on your machine. Get all the updates installed and try a doing a few things on it to see if it's fast & slick, like it's supposed to be. If it is, you're home. If it isn't, get an exact duplicate repacement of your original hard drive installed... right down to the same manufacturer, etc..
The thing to do next, is get your files and stuff back on your computer, but don't transfer anything like preferences and stuff. Just documents, audio and video files, etc.. Reset any system or app preferences fresh, yourself. Don't count on automatic routines to take care of that for you, 'cause that can mess your system up all over again. Do fresh reinstalls of any applications.
Last night I performed a clean install of Snow Leopard from the original system discs. This failed with no difference in performance. However, tonight I reinstalled the original 250g toshiba hdd, and did another clean install of Snow Leopard.
Now we seem to be getting somewhere - I do getting beach balls, but they seem to appear in logical places. e.g. Open everything creative suite application at once... As opposed to work for 30sec, beach ball for 30sec...
Things are looking up! Only problem now is, should i upgrade back to Lion again. (reverse reverse scrolling is killing my sleepy brain)