I bought a cheap $10 multitool at a department store, plus a $3 chain breaker. These have been totally fine for me, the tools are more than strong enough, even working on bolts so tight I had to use a torch to break them loose, I didn't break or bend the tools.

The separate chain breaker is nicer than the integrated ones I looked at.

I also picked up a basic shop tool kit at Nashbar when it was on sale for $35 or so, giving me freewheel tools, crankset puller, individual allen wrenches, all all that jazz.