This has been discussed plenty. I lean toward the AAB camp but certainly agree some versions are better than others. I would say Cowpoke is a bit better than Buckaroo. Better art in my opinion and the Buckaroo roto only has one "4" making it very hard to light four numbers in a row.
I owned Gold Strike and found it could be too easy, I would give the nod to El Dorado.
It's true what you say about Abra-Ca-Dabra/Team One. The art package is awesome on Abra while Team One is pretty weak. Sometimes great gameplay can make mediocre art less of a concern. I haven't played either though.
I find Astro's (AAB) art package to be really cool and Four Square (Replay) to be blah. Once again I haven't spent any time on either.