The tippmann paintball markers is a great line of paintball guns.  They are competitive no matter what level you play at, or what game you are playing from speed ball, woods ball, scenario play, or even just screwing around with freinds.  These guns are great for nearly any thing you do, and will be able to remain competitive with the expensive guns as you grow more advanced.

Tippmanns two most commercialized and most popular are the Tippmann A-5, and the Tippmann 98 Custom Pro.  Both these guns are fully customizable for your every paintball need.  Both these guns have very many advantages, and not so many disadvantages. 

The Tippmann A-5 is the fastest shooting tippmann gun on the market.  It has an automatic feed system that rotates and feeds up to 15 balls per second.  This is great and all if you are doing speed ball, but since this system is run on air, you eat up a lot of your co2.  But putting this aside you can still fully costumize and upgrade it to fit almost any need.  One of the best things I have noticed about this gun though is despite being more expenisive then the tippmann 98, the upgrades are generaly cheaper saving you more money in the long run.

The Tippmann 98 Custom Pro is the Best Tippmann 98 product on the market, it has a double trigger, drop foreward, and longer barrel, but best of all it is capable with the e-grip (also available on A-5).  This has a few upgrades that the A-5 doesn't have though, such as the low pressure kit.  This gun is more of a woods ball, or scenario rifle than the A-5 because it is more upgradeable and shoots a little slower.

The upgrades I would have on my 98 or A-5 for woods ball to make the ultimate would be: The Low pressure kit for the A-5, this allows you to maintain a constant air pressure and less breakage; a response trigger which would allow you to shoot faster, but not making it full auto and allowing you to set how fast you wish to shot; a flatline barrel, which using the backspin technology allows you a hundred feet farther (though consitant, seems to shot wierd until you figure it out then you oppenents better watch out because it does sting); collapsable stock, it adds comfort and is less expensive then 6 position stock; and a double trigger and drop foreward combination (standard on custom pro).

For speed ball I would: an electric hopper for faster firing; a e-grip, also for faster firing, a dye boom stick barrel for less breakage and more accuracy; a remote coil, so your gun is lighter without the tank and you can role and dive easier; and finaly i would use a double trigger, for faster firing. 

These guns would be extrmely competitive on almost any level.  They are great starter guns being th cost affective, as compared to the realy expensive paint ball guns.  They will surely last almost your whole life if taken care of.  And even as new guns are released they will still be competitive because of there upgrading capabilities, and after all guns don't kill people, people kill people.