Not as impressive as everyone else's 20+ collection but I'm proud of my stuff.
Tippmann 98c - First gun I ever bought, plus the only I've ever bought new.

Polished internals, double trigger, modified trigger spring for lighter pull, 14" SP Progressive barrel, dropforward.
2004-5 Spyder Pilot

Delrin ACS bolt, aftermarket velocity adjuster, halfblocked, 14" SP Inline barrel. Love this gun except it chops everything.
Only picture of me playing (so far), at D-day 2012 at Hogback Mountain, VA:
2009 Proto Matrix Rail - hated this gun, so many problems so I sold it.

Only thing I ever did was remove the trigger return spring for a lighter pull.
2003 Autococker Black Magic - also use it as a pump

J&J ram, CCM NoRise, Delrin bolt, Hooptie pump kit, CP detent, CP direct mount on/off ASA, aftermarket macroline. Love this gun more than life itself. The only problem I have ever had was from an HPR oring.
Invert Mini V2 - Just got this one so I can play on my school's team.

I put a Relay ASA on it because I accidently killed the stock one on the first day of play. Blew out the gauge too, I'm lucky I didn't kill anything else. Some solenoid stick but I'm not too concerned right now. Not my pic by the way. Haven't had a chance to use the good camera on it. Awesome little gun, modern tech is great when it works.
Many more to add as time goes on...