From the ones on your " to watch list" i’d move Minnesota Clay to the top personally
Other “must see” ones on your list are Shoot the Living and Pray for the Dead, Kill and Pray and The Bounty Killer
Have you seen Death Sentence? That is a must see to.
But opinions on Spaghettis varies widely and a lot is down to personal preference so its best to watch as many as you can
I think the Top 20 lists (see the front page) are pretty good representations of what most people consider to be “the best” however