for me, it would have to be
1. Any kind of tac modded systema M4
2. Any one of the TM Recoil series, with eagle 6 upgrades
3. ICS sportline series, great starter guns
4. TM Sig P226, or TM Glock 17, they just keep running, and are very reliable
5. TM VSR of sorts, just because of the numerous possibilities of upgrades and set ups
i choose these because i've owned numbers 2, 3, 4 and 5, and i've played with number 1 a lot