I’m going to reopen this topic in order to allow discussion about the issue at hand.
Note that we don’t allow discussion of specific hosting recommendations and such on these forums, because they’re very rarely useful or productive. So don’t go there. But if you’re having problems, then those problems can be discussed all you like.
If you’re getting frequent 404’s or “database connection” errors, then this is a sign of two things: overloaded server, or too much traffic for the account. The bottom line here is that no amount of optimization or plugin trickery is going to solve this problem. You need a more beefy host. You can’t run a site that gets 10 hits a second on a $5 a month host. Like it or not, webhosting is pay to play.
So, if you’re having trouble on a lower tier hosting, move up a tier. Maybe look at a VPS or something. Or a better host that has better experience with WordPress and such. Some hosts offer optimized hosting systems for WP. The bottom line is that you need to figure out where your traffic is, how much of it you have, and then choose a system that gets you the most for your money.
And if all you want to do is write a blog and not worry about this sort of thing, look into managed hosting instead. It costs more, but you don’t have to deal with low level hosting issues. Thus the “managed”.