05 Tacoma over an 04?

Somewhat have convinced myself to go buy an 05 over an 04. If anyone has a good reason not to PLEASE let me know!

 

Depends on what body style / engine / drive type you want at least - could influence people's advice.

 

2005 was the 1st year of the model change. They had quite a few issues.
I would opt for a 1st gen any day over an early 2nd gen. Depends on mileage and abuse.

 

04

 

Well.... we can't read your mind and we don't know what you like or dislike. If you've got two trucks in mind.....
Frame, frame, frame, condition, mileage, cost, options, etc.

Did I mention....frame? Both trucks fall (or fell) under a frame recall. Both trucks would've had the option of having the frame replaced.
The 2004 would've either been replaced or sprayed with undercoating. Do not buy a truck with undercoating. It's risky buying a truck that hasn't had the frame replaced. Before buying anything, I'd have Toyota inspect the frame and/or confirm its had the frame replaced.
And DO NOT assume the frame looks good just by looking on the outside. The frames are rotting from the inside out. CYA - and have Toyota inspect it.