21. HNT-151 Hornet - Somehow manages to be worse than the Thorn. 5/8/5 is simply too slow for a 20-ton 'Mech.
20. THE-S Thorn - 6/9/0 is also too slow for a 20-ton 'Mech.
19. OTT-7J Ostscout - I feel like the Spider's undergunned, so halving the firepower doesn't move me.
18. FLE-4 Flea - Love the large laser, love the flamer (if only it was forward-mounted), but hate the move curve and hate the pointless small lasers. The FLE-15 isn't bad but still has pointless small lasers and lacks the wow factor of a large laser on a bug chassis.
17. FLC-4N Falcon - Not actually that terrible compared to its close cousin the Stinger, but the extremely questionable decision to rear-mount the MGs consigns the Falcon to the dustbin of history.
16. RVN-1X Raven - Well, if you're using the rules for its electronic equipment, it's the only thing that carries it in its era, period. If you're not, it's a heavier, slower Commando with slightly different weapons.
15. HSR-300-D Hussar - There are two 9/14 options in 3025 tech, and this is the bad one. The speed is great, the firepower is great, but my god the armor.
14. FS9-H Firestarter - Respectable firepower and armor and a decent movement curve, and I'm a big fan of incendiary 'Mechs, but the heat curve is the real killer.
13. VLK-QA Valkyrie - I've never liked the LRM-10 and I never will, but the Valk is at least fairly well-rounded. I can't really say anything bad about it... other than it carries an LRM-10. ;)
12. COM-2D Commando - Lyran that I am (it's only this high on the list because of that), would that I could love the Commando like I should. It just never delivers anything but a horrible, explosive death to its pilot.
11. STG-3R Stinger - More notable for being ubiquitous than being great. Really good bugs want to be 7/11 rather than 6/9/6 (hence all this business about the Assassin), but the Stinger can do OK.
10. WSP-1A Wasp - Can't really break up the Stinger and the Wasp, but I give the edge to the Wasp due to a slightly longer range and its effectiveness as an inferno carrier.
9. SDR-5V Spider - Yeah, it jumps far, but it never seems to perform up to spec. Backstabbing is a great role, but the backstabber needs to have something to stab with when it gets there.
8. UM-R60 UrbanMech - I'm not as nutty for the Urbie as some, but when used in city defense and played smart it can be very effective.
7. JVN-10N Javelin - Not really overwhelming, but certainly a respectable entrant, capable of delivering a nice punch.
6. WLF-1 Wolfhound - Certainly the best of the 6/9/0 machines, but that's not saying a whole lot. Personal experience hasn't been great, but I acknowledge that on paper it delivers.
5. MON-67 Mongoose - Good on paper, but I've got limited experience with them, not all of it good. I like my lights to have more than one trick, personally.
4. JR7-D Jenner - Underarmored, runs hot and tends to explode, but if you can get past that, hoo buddy.
3. LCT-1V Locust - The ur-scout, and basically the benchmark against which all other light 'Mechs are judged. Quails under serious fire, but so do all of its fellow 20-tonners -- at least it has the ground speed to get out of trouble and the MGs to chop up infantry.
2. PNT-9R Panther - The poor man/Drac's version of the much-lauded Vindicator. It doesn't do what other lights do, it does what heavies do -- deliver PPC fire. But the jump jets make it more mobile at its job than a Warhammer or Marauder, and it's got good armor for its tonnage. It's not perfect, but I've seen it get the job done too often to discount 'em.
1. HER-1A Hermes - There are two 9/14 options in 3025 tech, and this is the good one. A sleeper, but an effective one, kitted out with the flamer, which I remain convinced is among the best weapons under TW. Granted it has less armor than the Mongoose, but it also does what it can't -- anti-infantry and incendiary work -- and goes faster, too.
Of course, your mileage may vary. My opinion as to #1 is probably colored by seeing a HER-1A get the kill shot on 4 enemy 'Mechs in a single battle -- finishing with a charge on a Warhammer that legged and gyro'ed the Hermes but also dropped the Whammy alongside it.