While their approval rating may be at some of the lowest levels ever, it's financially a good time to be a member of Congress.

Lawmakers' $174,000 annual salary is more than three times the average American's median income ($49,909), and the retirement and health benefits are generous -- members are fully vested after only five years of service and eligible for pension at age 50.

But the perks don't stop there. In fact, some of them are considered borderline criminal.

Political Perk #1: Congress Nearly Gets Away With Insider Trading Every Day

Making trades based on non-public information is very illegal. Insider trading convictions come with severe fines (up to $5 million for each 'willful' violation) and possible jail time.

Unless you're a member of Congress. There's absolutely nothing in the Securities and Exchange Commission Act that prevents lawmakers and federal employees from profiting on inside information they learn just doing their jobs.

Strangely enough, many representatives also outperform the average investor. A recent university study looked at stock transactions by 300 House representatives from 1985 to 2001 found they beat the performance of the stock market by about 6% annually. Senators outperformed other investor averages by nearly 12% annually. Representatives who invested frequently performed better than corporate insiders.

While not totally condemning, the numbers are certainly interesting. One of the study's researchers said, 'We have every reason to believe they are trading on information that the rest of us don't have.'

In 2006, Rep. Louise Slaughter (Dem -- N.Y.) introduced the Stop Trading on Congressional Knowledge (STOCK) Act, a bill that would hold members of Congress and federal employees to the same insider trading standards as everyone else.

The bill was re-introduced in 2007, 2009, and most recently, March 2011. It hasn't been heard from since.

Political Perk #2: Great Tax Breaks and Bonuses

Since Congress writes and approves the tax code, it's not surprising that they wrote in a few bonuses for themselves.

Members of Congress are able to deduct $3,000 from their annual income tax for any expenses incurred outside of their home state or district.

Additionally, all the of the perks given to the members of Congress-- including free parking at the office and D.C. airports, child daycare, free meals at the legislative dining hall, and cheap membership to the house gym -- are tax free.

And the perks don't stop when they retire: In addition to free health benefits and a generous pension, former members of Congress can send mail for free, courtesy of the U.S. taxpayer.

Additionally, campaign funds can be spent on meals and entertainment for constituents, as well as travel, anytime of the year, whether in session or not.

Political Perk #3: Free Travel and Trips

Want to take a 'fact finding' trip to France? Not a problem if you are a member of Congress, so long as it's 'business' related. Just join a committee and chances are you will need to carry out one of these strictly-business-trips overseas at least once.

Last year, the Congressional Research Council found that it is nearly impossible for the public to find out which Congressional members make trips and where they go. What's more, current laws don't impose any spending limits on these government trips. The U.S. Treasury simply refills the travel funds on an 'as-needed' basis.

Additionally, Congress members get to travel between D.C. and their home district for free as often as they like.

[InvestingAnswers Feature: 6 Projects You Won't Believe the Government is Funding]

Political Perk #4: Almost Half the Year Off for Vacation

When all that trip-taking wears them down, members of Congress can always fall back on their vacation time. Out of 260 working days in a year, Congress only works 137 of them.

In the first 42 weeks of this year, Congress members worked an average of 2.67 days per week. Amazingly, that's actually a better attendance rate than usual -- the last two years, our legislative branch only worked 111 days.

Political Perk #5: They Can Vote For Their Own Pay Raise

Can you imagine a workplace where the employees could choose to give themselves a raise, regardless of the financial shape of the place they work for, the current economic climate or even their own job performance?

That's how it works for members of Congress. They don't have to prove to a boss that they deserve a higher salary; they only need to convince one another that it is a good idea. Then they all vote on it.

Since the 'Congressional cost-of-living adjustment (COLA)' rule was enacted in 1990, Congress has accepted an annual raise 13 times. Every year, the rule automatically increases congressional salaries in accordance to price indexes. In fact, the only time representatives don't get a raise is if they vote against it, which they did for 2010 and 2011.

The Investing Answer: If these perks tell you anything, it's that being a member of Congress has far more of an upside than simply just power, prestige and mass influence on laws. Unfortunately, it comes at the expense of taxpayers and that's no laughing matter. Be sure you understand the policies your representative stands for and vote to make sure your voice is heard.