Moneydance is a full-featured personal finance manager with online banking and bill payment, budget tracking, scheduling of transactions, and investment management tools. It's perfect for older Macs, requiring only 4.8 MB of hard disk space and a thrifty 128 MB of RAM.
The US$39.99 Mac app (upgrade free for existing users) includes a ton of bug fixes and improvements. There's a new popup display of transaction information and splits when you hold down the alt key when hovering over a transaction, plus improved graphs, the ability to store online passwords in the data file (encryption must be enabled), and more. A free trial is available for those who are curious.