The question is what would be viable.

I am in the market for maybe 2 lens.
What I have is:
450d
1x EFS 55-250mm (Kit lens)
1x EFS 18-55mm (Kit Lens)

The 55-250 is basically a piece of junk. It is all loose in the body. It does produce some good shots and lots of bad shots, but I want more. I would use this lens for 80% of my shots.

The 18-55 works well and I have no problems with it.

I would like something for more close up shots though, not necessarily a macro lens though.
Would tubes be a viable option.

Opportunity to get some gear before we leave Thailand.

Any ideas/views on what would be good buying greatly appreciated.