First MTB for a newbie

Hi there, it's my first post here and I just recently got into the MTB scene. I won't be riding frequently, just every couple of weekends on trails and such, and I have narrowed down my choice to 3 bikes.

1: Mongoose Rockadile ALD '03 (27lbs) - $315
The Mongoose Rockadile ALD mountain bike for men combines Shimano Acera derailleurs and Shimano EF-29 EZ-Fire shifters for easy and reliable gear changes while you ride the trail. Promax MGD 4.0 mechanical brakes offers strong stopping power and a MOZO USA R-120A alloy suspension fork with 76mm travel provides increases handling and shock absorption. This bike comes equipped with Kenda Koyote tires on Alex SCE-17 alloy rims.

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2: Mongoose Rockadile ALD '04 (27lbs?) - $400
6061 Alloy Hardtail Frame w/ Disc Brake Mount, Zero Stack Headset MOZO USA Vibe-R Suspension Fork w/ 76mm Travel, Preload Adjust Shimano Acera 24-Spd Drivetrain w/ EF-35 Shifters; TruVativ ISO-Flow Crankset Tektro IO Mechanical Disc Brakes Alex Rims w/ Formula/Shimano Disc Hubs; Kenda Koyote 1.95” Tires

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3: Giant Yukon '04 (? lbs) - $500
frame Supersized ALUXX butted aluminum, w/intergrated gusset, disc brake mount

fork SR/Suntour XC75 Magnesium suspension w/pre-load adjustment

derailleur Front: Shimano Acera, Rear: Shimano Alivio

derailleurshifters Shimano EF-29, 8-speed
cranks Giant, 22/32/42T

pedals Steel w/ resin body

handlebar Alloy 1.25" riser

stem Alloy 1 1/8 Ahead, 25 degree rise

headset Ahead 1 1/8

brakes Hayes HMX-2 Disc, 6" rotors

saddle Giant Groove Plus, VARIABLE-DENSITY MTB with Kevlar bumpers

seatpost Alloy micro-adjust, 27.2, QR Seat lever

rims Alloy, 32H doublewall, black w/ brushed sidewall

hubs Alloy, QR, 32H, double seals

tires WTB Weirwolf 26x2.0

cassette Shimano 11-30T, 8 speed

I'm leaning towards the Rockadile '03 simply because it's the cheapest and I think the '04 isn't worth the extra $85 for newer components or the $185 for the Giant with the more widely known name brands. Any suggestions are appreciated.