The electric yellow one I bought at Costco works real well for around home. I use it hard & it's still ticking after 3 years. Brand: "Yardman". It was around $80 or $90, plus around $15 for a real long heavy extension cord at Home Depot.
It's surprisingly powerful, & does a good job at lawn edging too.
The gardner guys around here who do serious weed whacking use gas powered ones with a triangular steel blade instead of cutting line, but I've never owned one like that. I suppose that'd be better, because you could probably trim bushes with it too. I've seen brands STIHL & Huskvarna.
But they're expensive & need maintenance. Mine: yeah it's electric, which is badmouthed in posts above, but real powerful, no maintenance, if it breaks no great regret to toss & get a new one.