How much is it worth to have a good time preparing your tax returns? That may be possible for owners of personal computers, who this year can draw on a broader selection of software programs designed to help taxpayers prepare their federal returns.

The manufacturers promise that the software will speed and simplify tax preparation, and the programs appear capable of making good on the promise, for many upper-income taxpayers. They can even make the tax-filing chore pleasant.

The most important factor to consider before buying a program is the complexity of your return.

A single taxpayer whose income comes primarily from wages, and whose itemized deductions are simple and straightforward, will have a harder time justifying an investment in the software, except as entertainment. At the other end of the spectrum, a taxpayer whose return involves tough judgment calls on the handling of tax shelters won't find the answers in the programs.

The simpler programs, such as Swiftax, sell for $49.95 list ($37.46 discounted) and will carry out the basic calculations for the long form and the most common schedules.

More complex programs, such as Tax Advantage (list price $69.95), can exchange information with other programs on which a taxpayer can keep track of expenses and other tax data during the year. For the extremely well-organized, this is a major plus.

One of the better programs is a new one, a software companion to the familiar J. K. Lasser tax guide, "Your Income Tax." It is designed for the IBM PC, PC XT and personal computers such as the Compaq that are fully compatible with the IBM PC. The publisher, Simon & Schuster Inc., emphasizes the word "fully" so careful checking with a dealer is advisable. The Lasser software carries a list price of $79.95. Like other programs, it is tax deductible and has yearly updates.

And like some other software tax programs, it includes a questionnaire that must be completed first, allowing the program to double-check some of the basic decisions a taxpayer makes in completing the return.

The program knows exactly how it wants the information entered. When the questionnaire asks your age, and you respond with anything but a number, it stops and beeps at you.

With the questionnaire completed, a user calls up a replica of the 1040 on the screen and moves down the form, line by line, typing in income and other information.

The most appealing part of this software program is its use of windows, a technique that divides the screen into separate compartments to display different information.

In this case, windows permit a simple transition from the 1040 to Schedule B, for example, to include interest and dividend income. If you answered "yes" to the interest income question on the questionnaire, the program requires you to complete Schedule B. Typing one of the function keys brings the schedule into view on the screen, in its own window. When Schedule B is completed, the information is automatically entered on the 1040, which then reappears on the screen. No copying errors. For those with color monitors, the text and windows are in bright colors -- reds, blues and yellows -- helping relieve the drudgery.

The program also has an on-screen calculator, which appears in its own window when needed. And at each line of a form or schedule, a reference is provided to the appropriate paragraph in the Lasser tax guide, which comes with the software program.

When all the numbers have been supplied and all the information provided, the program computes the income tax.

The program's biggest weakness is its inability to print the return information on IRS forms. But for $195, a PC owner can get a program called PC/Taxcut that does print returns on official IRS forms, ready for mailing. This is the third year PC/Taxcut has been issued by Best Programs of Alexandria, and the 1984 version contains more than two dozen modifications to comply with new provisions of the tax code. For those who bought the previous programs, the update costs $75.

PC/Taxcut also provides analysis of some of the more complex questions that upper-income taxpayers may face. For example, taxpayers who received deductions, lower tax rates or exemptions on investment income may have to pay an Alternative Minimum Tax instead of the customary tax. And PC/Taxcut will walk a taxpayer through the calculations.

But PC/Taxcut contains the disclaimer common to all the programs -- when in doubt, call an expert. The programs aren't much help in a confrontation with an IRS auditor.